55815961 has 2 divisors, whose sum is σ = 55815962. Its totient is φ = 55815960.

The previous prime is 55815953. The next prime is 55815967. The reversal of 55815961 is 16951855.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55041561 + 774400 = 7419^2 + 880^2 .

It is a cyclic number.

It is not a de Polignac number, because 55815961 - 2³ = 55815953 is a prime.

It is not a weakly prime, because it can be changed into another prime (55815967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27907980 + 27907981.

It is an arithmetic number, because the mean of its divisors is an integer number (27907981).

Almost surely, 2^55815961 is an apocalyptic number.

It is an amenable number.

55815961 is a deficient number, since it is larger than the sum of its proper divisors (1).

55815961 is an equidigital number, since it uses as much as digits as its factorization.

55815961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54000, while the sum is 40.

The square root of 55815961 is about 7471.0080310491. The cubic root of 55815961 is about 382.1666647542.

The spelling of 55815961 in words is "fifty-five million, eight hundred fifteen thousand, nine hundred sixty-one".