1957407681 has 4 divisors (see below), whose sum is σ = 2609876912. Its totient is φ = 1304938452.

The previous prime is 1957407677. The next prime is 1957407701. The reversal of 1957407681 is 1867047591.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1867047591 = 3 ⋅622349197.

It is not a de Polignac number, because 1957407681 - 2² = 1957407677 is a prime.

It is a super-2 number, since 2×1957407681² = 7662889659275595522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1957407681.

It is not an unprimeable number, because it can be changed into a prime (1957407631) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 326234611 + ... + 326234616.

It is an arithmetic number, because the mean of its divisors is an integer number (652469228).

Almost surely, 2^1957407681 is an apocalyptic number.

It is an amenable number.

1957407681 is a deficient number, since it is larger than the sum of its proper divisors (652469231).

1957407681 is an equidigital number, since it uses as much as digits as its factorization.

1957407681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 652469230.

The product of its (nonzero) digits is 423360, while the sum is 48.

The square root of 1957407681 is about 44242.6002965468. The cubic root of 1957407681 is about 1250.9129716372.

The spelling of 1957407681 in words is "one billion, nine hundred fifty-seven million, four hundred seven thousand, six hundred eighty-one".