1540997931 has 16 divisors (see below), whose sum is σ = 2279445120. Its totient is φ = 918107520.

The previous prime is 1540997903. The next prime is 1540997947. The reversal of 1540997931 is 1397990451.

It is not a de Polignac number, because 1540997931 - 2²⁷ = 1406780203 is a prime.

It is a super-2 number, since 2×1540997931² = 4749349246692561522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1540997951) 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, 393790 + ... + 397683.

It is an arithmetic number, because the mean of its divisors is an integer number (142465320).

Almost surely, 2^1540997931 is an apocalyptic number.

1540997931 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1540997931 is a deficient number, since it is larger than the sum of its proper divisors (738447189).

1540997931 is a wasteful number, since it uses less digits than its factorization.

1540997931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 791546.

The product of its (nonzero) digits is 306180, while the sum is 48.

The square root of 1540997931 is about 39255.5464998260. The cubic root of 1540997931 is about 1155.0497360566.

The spelling of 1540997931 in words is "one billion, five hundred forty million, nine hundred ninety-seven thousand, nine hundred thirty-one".