55517881 has 2 divisors, whose sum is σ = 55517882. Its totient is φ = 55517880.

The previous prime is 55517843. The next prime is 55517893. The reversal of 55517881 is 18871555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44355600 + 11162281 = 6660^2 + 3341^2 .

It is a cyclic number.

It is not a de Polignac number, because 55517881 - 2¹¹ = 55515833 is a prime.

It is a super-2 number, since 2×55517881² = 6164470221460322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (55517831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27758940 + 27758941.

It is an arithmetic number, because the mean of its divisors is an integer number (27758941).

Almost surely, 2^55517881 is an apocalyptic number.

It is an amenable number.

55517881 is a deficient number, since it is larger than the sum of its proper divisors (1).

55517881 is an equidigital number, since it uses as much as digits as its factorization.

55517881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56000, while the sum is 40.

The square root of 55517881 is about 7451.0322103719. The cubic root of 55517881 is about 381.4851414791.

The spelling of 55517881 in words is "fifty-five million, five hundred seventeen thousand, eight hundred eighty-one".