1581491400 has 48 divisors (see below), whose sum is σ = 4902625200. Its totient is φ = 421730880.

The previous prime is 1581491399. The next prime is 1581491413. The reversal of 1581491400 is 41941851.

It is a super-2 number, since 2×1581491400² = 5002230096547920000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1317310 + ... + 1318509.

It is an arithmetic number, because the mean of its divisors is an integer number (102138025).

Almost surely, 2^1581491400 is an apocalyptic number.

1581491400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1581491400 is an abundant number, since it is smaller than the sum of its proper divisors (3321133800).

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

1581491400 is a wasteful number, since it uses less digits than its factorization.

1581491400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2635838 (or 2635829 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 1581491400 is about 39767.9695232231. The cubic root of 1581491400 is about 1165.0796362270.

The spelling of 1581491400 in words is "one billion, five hundred eighty-one million, four hundred ninety-one thousand, four hundred".