1156555020 has 48 divisors (see below), whose sum is σ = 3242792448. Its totient is φ = 307992000.

The previous prime is 1156555013. The next prime is 1156555021. The reversal of 1156555020 is 205556511.

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

It is not an unprimeable number, because it can be changed into a prime (1156555021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32227 + ... + 57893.

It is an arithmetic number, because the mean of its divisors is an integer number (67558176).

Almost surely, 2^1156555020 is an apocalyptic number.

1156555020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1156555020 is an abundant number, since it is smaller than the sum of its proper divisors (2086237428).

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

1156555020 is a wasteful number, since it uses less digits than its factorization.

1156555020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26430 (or 26428 counting only the distinct ones).

The product of its (nonzero) digits is 7500, while the sum is 30.

The square root of 1156555020 is about 34008.1610793645. The cubic root of 1156555020 is about 1049.6763991455.

The spelling of 1156555020 in words is "one billion, one hundred fifty-six million, five hundred fifty-five thousand, twenty".