56721521279 has 2 divisors, whose sum is σ = 56721521280. Its totient is φ = 56721521278.

The previous prime is 56721521267. The next prime is 56721521287. The reversal of 56721521279 is 97212512765.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56721521279 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56721521209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28360760639 + 28360760640.

It is an arithmetic number, because the mean of its divisors is an integer number (28360760640).

Almost surely, 2^56721521279 is an apocalyptic number.

56721521279 is a deficient number, since it is larger than the sum of its proper divisors (1).

56721521279 is an equidigital number, since it uses as much as digits as its factorization.

56721521279 is an evil number, because the sum of its binary digits is even.

The product of its digits is 529200, while the sum is 47.

The spelling of 56721521279 in words is "fifty-six billion, seven hundred twenty-one million, five hundred twenty-one thousand, two hundred seventy-nine".