55165021 has 2 divisors, whose sum is σ = 55165022. Its totient is φ = 55165020.

The previous prime is 55165003. The next prime is 55165067. The reversal of 55165021 is 12056155.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47403225 + 7761796 = 6885^2 + 2786^2 .

It is a cyclic number.

It is not a de Polignac number, because 55165021 - 2⁹ = 55164509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55165091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27582510 + 27582511.

It is an arithmetic number, because the mean of its divisors is an integer number (27582511).

Almost surely, 2^55165021 is an apocalyptic number.

It is an amenable number.

55165021 is a deficient number, since it is larger than the sum of its proper divisors (1).

55165021 is an equidigital number, since it uses as much as digits as its factorization.

55165021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 55165021 is about 7427.3158677950. The cubic root of 55165021 is about 380.6752099642.

The spelling of 55165021 in words is "fifty-five million, one hundred sixty-five thousand, twenty-one".