1957997591 has 4 divisors (see below), whose sum is σ = 2135997384. Its totient is φ = 1779997800.

The previous prime is 1957997563. The next prime is 1957997609.

1957997591 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1957997591 - 2³⁰ = 884255767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1957997551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88999880 + ... + 88999901.

It is an arithmetic number, because the mean of its divisors is an integer number (533999346).

Almost surely, 2^1957997591 is an apocalyptic number.

1957997591 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1957997591 is a deficient number, since it is larger than the sum of its proper divisors (177999793).

1957997591 is a wasteful number, since it uses less digits than its factorization.

1957997591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177999792.

The product of its digits is 8037225, while the sum is 62.

The square root of 1957997591 is about 44249.2665588934. The cubic root of 1957997591 is about 1251.0386228510.

The spelling of 1957997591 in words is "one billion, nine hundred fifty-seven million, nine hundred ninety-seven thousand, five hundred ninety-one".