20571572616 has 128 divisors (see below), whose sum is σ = 59875200000. Its totient is φ = 5768692992.

The previous prime is 20571572591. The next prime is 20571572629. The reversal of 20571572616 is 61627517502.

It is a happy number.

It is a super-2 number, since 2×20571572616² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1954135 + ... + 1964633.

It is an arithmetic number, because the mean of its divisors is an integer number (467775000).

Almost surely, 2^20571572616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20571572616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29937600000).

20571572616 is an abundant number, since it is smaller than the sum of its proper divisors (39303627384).

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

20571572616 is a wasteful number, since it uses less digits than its factorization.

20571572616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10731 (or 10727 counting only the distinct ones).

The product of its (nonzero) digits is 176400, while the sum is 42.

The spelling of 20571572616 in words is "twenty billion, five hundred seventy-one million, five hundred seventy-two thousand, six hundred sixteen".