55661939 has 2 divisors, whose sum is σ = 55661940. Its totient is φ = 55661938.

The previous prime is 55661891. The next prime is 55661981. The reversal of 55661939 is 93916655.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 55661939 - 2¹⁶ = 55596403 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 55661939.

It is not a weakly prime, because it can be changed into another prime (55661999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27830969 + 27830970.

It is an arithmetic number, because the mean of its divisors is an integer number (27830970).

Almost surely, 2^55661939 is an apocalyptic number.

55661939 is a deficient number, since it is larger than the sum of its proper divisors (1).

55661939 is an equidigital number, since it uses as much as digits as its factorization.

55661939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 218700, while the sum is 44.

The square root of 55661939 is about 7460.6929302847. The cubic root of 55661939 is about 381.8148161749.

The spelling of 55661939 in words is "fifty-five million, six hundred sixty-one thousand, nine hundred thirty-nine".