55515569 has 2 divisors, whose sum is σ = 55515570. Its totient is φ = 55515568.

The previous prime is 55515547. The next prime is 55515571. The reversal of 55515569 is 96551555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50225569 + 5290000 = 7087^2 + 2300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55515569 is a prime.

It is a super-2 number, since 2×55515569² = 6163956802787522, which contains 22 as substring.

Together with 55515571, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (55515529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27757784 + 27757785.

It is an arithmetic number, because the mean of its divisors is an integer number (27757785).

Almost surely, 2^55515569 is an apocalyptic number.

It is an amenable number.

55515569 is a deficient number, since it is larger than the sum of its proper divisors (1).

55515569 is an equidigital number, since it uses as much as digits as its factorization.

55515569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 168750, while the sum is 41.

The square root of 55515569 is about 7450.8770624672. The cubic root of 55515569 is about 381.4798458526.

The spelling of 55515569 in words is "fifty-five million, five hundred fifteen thousand, five hundred sixty-nine".