55787217 has 16 divisors (see below), whose sum is σ = 80248320. Its totient is φ = 34341632.

The previous prime is 55787203. The next prime is 55787219. The reversal of 55787217 is 71278755.

It is not a de Polignac number, because 55787217 - 2⁴ = 55787201 is a prime.

It is a super-2 number, since 2×55787217² = 6224427161210178, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55787219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7617 + ... + 13022.

It is an arithmetic number, because the mean of its divisors is an integer number (5015520).

Almost surely, 2^55787217 is an apocalyptic number.

It is an amenable number.

55787217 is a deficient number, since it is larger than the sum of its proper divisors (24461103).

55787217 is a wasteful number, since it uses less digits than its factorization.

55787217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20712.

The product of its digits is 137200, while the sum is 42.

The square root of 55787217 is about 7469.0840803943. The cubic root of 55787217 is about 382.1010509964.

The spelling of 55787217 in words is "fifty-five million, seven hundred eighty-seven thousand, two hundred seventeen".