55728131 has 2 divisors, whose sum is σ = 55728132. Its totient is φ = 55728130.

The previous prime is 55728119. The next prime is 55728133. The reversal of 55728131 is 13182755.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 55728131 - 2¹⁸ = 55465987 is a prime.

It is a super-2 number, since 2×55728131² = 6211249169506322, which contains 22 as substring.

Together with 55728133, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (55728133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27864065 + 27864066.

It is an arithmetic number, because the mean of its divisors is an integer number (27864066).

Almost surely, 2^55728131 is an apocalyptic number.

55728131 is a deficient number, since it is larger than the sum of its proper divisors (1).

55728131 is an equidigital number, since it uses as much as digits as its factorization.

55728131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8400, while the sum is 32.

The square root of 55728131 is about 7465.1276613331. The cubic root of 55728131 is about 381.9661049209.

The spelling of 55728131 in words is "fifty-five million, seven hundred twenty-eight thousand, one hundred thirty-one".