55415557 has 2 divisors, whose sum is σ = 55415558. Its totient is φ = 55415556.

The previous prime is 55415537. The next prime is 55415567. The reversal of 55415557 is 75551455.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38118276 + 17297281 = 6174^2 + 4159^2 .

It is a cyclic number.

It is not a de Polignac number, because 55415557 - 2¹⁹ = 54891269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55415537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27707778 + 27707779.

It is an arithmetic number, because the mean of its divisors is an integer number (27707779).

Almost surely, 2^55415557 is an apocalyptic number.

It is an amenable number.

55415557 is a deficient number, since it is larger than the sum of its proper divisors (1).

55415557 is an equidigital number, since it uses as much as digits as its factorization.

55415557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 87500, while the sum is 37.

The square root of 55415557 is about 7444.1626124098. The cubic root of 55415557 is about 381.2506278947.

The spelling of 55415557 in words is "fifty-five million, four hundred fifteen thousand, five hundred fifty-seven".