1581170220 has 180 divisors, whose sum is σ = 5770306080. Its totient is φ = 361392192.

The previous prime is 1581170209. The next prime is 1581170231. The reversal of 1581170220 is 220711851.

It is an interprime number because it is at equal distance from previous prime (1581170209) and next prime (1581170231).

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×1581170220² = 5000198529229696800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 69421 + ... + 89339.

It is an arithmetic number, because the mean of its divisors is an integer number (32057256).

Almost surely, 2^1581170220 is an apocalyptic number.

1581170220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1581170220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2885153040).

1581170220 is an abundant number, since it is smaller than the sum of its proper divisors (4189135860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1581170220 is a wasteful number, since it uses less digits than its factorization.

1581170220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19954 (or 19936 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 27.

The square root of 1581170220 is about 39763.9311436885. The cubic root of 1581170220 is about 1165.0007601289. Note that the first 3 decimals are identical.

The spelling of 1581170220 in words is "one billion, five hundred eighty-one million, one hundred seventy thousand, two hundred twenty".