1220257740 has 96 divisors (see below), whose sum is σ = 3701718720. Its totient is φ = 300338688.

The previous prime is 1220257697. The next prime is 1220257781. The reversal of 1220257740 is 477520221.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1220257698 and 1220257707.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 127192 + ... + 136448.

It is an arithmetic number, because the mean of its divisors is an integer number (38559570).

Almost surely, 2^1220257740 is an apocalyptic number.

1220257740 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 1220257740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1850859360).

1220257740 is an abundant number, since it is smaller than the sum of its proper divisors (2481460980).

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

1220257740 is a wasteful number, since it uses less digits than its factorization.

1220257740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9308 (or 9280 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 30.

The square root of 1220257740 is about 34932.1877356687. The cubic root of 1220257740 is about 1068.6049715316.

Adding to 1220257740 its reverse (477520221), we get a palindrome (1697777961).

The spelling of 1220257740 in words is "one billion, two hundred twenty million, two hundred fifty-seven thousand, seven hundred forty".