55721566737 has 12 divisors (see below), whose sum is σ = 83467697040. Its totient is φ = 37147710996.

The previous prime is 55721566717. The next prime is 55721566753. The reversal of 55721566737 is 73766512755.

55721566737 is a `hidden beast` number, since 5 + 5 + 7 + 2 + 1 + 566 + 73 + 7 = 666.

It is not a de Polignac number, because 55721566737 - 2¹² = 55721562641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (55721566717) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 114653187 + ... + 114653672.

It is an arithmetic number, because the mean of its divisors is an integer number (6955641420).

Almost surely, 2^55721566737 is an apocalyptic number.

It is an amenable number.

55721566737 is a deficient number, since it is larger than the sum of its proper divisors (27746130303).

55721566737 is an equidigital number, since it uses as much as digits as its factorization.

55721566737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229306874 (or 229306862 counting only the distinct ones).

The product of its digits is 9261000, while the sum is 54.

The spelling of 55721566737 in words is "fifty-five billion, seven hundred twenty-one million, five hundred sixty-six thousand, seven hundred thirty-seven".