56121731 has 2 divisors, whose sum is σ = 56121732. Its totient is φ = 56121730.

The previous prime is 56121707. The next prime is 56121733. The reversal of 56121731 is 13712165.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 56121731 - 2¹⁰ = 56120707 is a prime.

It is a super-2 number, since 2×56121731² = 6299297380872722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 56121733, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 56121731.

It is not a weakly prime, because it can be changed into another prime (56121733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28060865 + 28060866.

It is an arithmetic number, because the mean of its divisors is an integer number (28060866).

Almost surely, 2^56121731 is an apocalyptic number.

56121731 is a deficient number, since it is larger than the sum of its proper divisors (1).

56121731 is an equidigital number, since it uses as much as digits as its factorization.

56121731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1260, while the sum is 26.

The square root of 56121731 is about 7491.4438528230. The cubic root of 56121731 is about 382.8632538155.

Adding to 56121731 its reverse (13712165), we get a palindrome (69833896).

The spelling of 56121731 in words is "fifty-six million, one hundred twenty-one thousand, seven hundred thirty-one".