55591817 has 2 divisors, whose sum is σ = 55591818. Its totient is φ = 55591816.

The previous prime is 55591813. The next prime is 55591831. The reversal of 55591817 is 71819555.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48706441 + 6885376 = 6979^2 + 2624^2 .

It is a cyclic number.

It is not a de Polignac number, because 55591817 - 2² = 55591813 is a prime.

It is a super-2 number, since 2×55591817² = 6180900234722978, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (55591813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27795908 + 27795909.

It is an arithmetic number, because the mean of its divisors is an integer number (27795909).

Almost surely, 2^55591817 is an apocalyptic number.

It is an amenable number.

55591817 is a deficient number, since it is larger than the sum of its proper divisors (1).

55591817 is an equidigital number, since it uses as much as digits as its factorization.

55591817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 63000, while the sum is 41.

The square root of 55591817 is about 7455.9920198455. The cubic root of 55591817 is about 381.6544141127.

The spelling of 55591817 in words is "fifty-five million, five hundred ninety-one thousand, eight hundred seventeen".