56961691 has 4 divisors (see below), whose sum is σ = 57601800. Its totient is φ = 56321584.

The previous prime is 56961661. The next prime is 56961733. The reversal of 56961691 is 19616965.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56961691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56961661) 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, 319921 + ... + 320098.

It is an arithmetic number, because the mean of its divisors is an integer number (14400450).

Almost surely, 2^56961691 is an apocalyptic number.

56961691 is a deficient number, since it is larger than the sum of its proper divisors (640109).

56961691 is an equidigital number, since it uses as much as digits as its factorization.

56961691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640108.

The product of its digits is 87480, while the sum is 43.

The square root of 56961691 is about 7547.2969333398. The cubic root of 56961691 is about 384.7638761269.

It can be divided in two parts, 5 and 6961691, that added together give a palindrome (6961696).

The spelling of 56961691 in words is "fifty-six million, nine hundred sixty-one thousand, six hundred ninety-one".