55772217 has 12 divisors (see below), whose sum is σ = 84062784. Its totient is φ = 35564760.

The previous prime is 55772203. The next prime is 55772237. The reversal of 55772217 is 71227755.

It is not a de Polignac number, because 55772217 - 2⁷ = 55772089 is a prime.

It is a super-2 number, since 2×55772217² = 6221080378190178, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (55772237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 134509 + ... + 134922.

It is an arithmetic number, because the mean of its divisors is an integer number (7005232).

Almost surely, 2^55772217 is an apocalyptic number.

It is an amenable number.

55772217 is a deficient number, since it is larger than the sum of its proper divisors (28290567).

55772217 is a wasteful number, since it uses less digits than its factorization.

55772217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269460 (or 269457 counting only the distinct ones).

The product of its digits is 34300, while the sum is 36.

The square root of 55772217 is about 7468.0798737025. The cubic root of 55772217 is about 382.0668016358.

The spelling of 55772217 in words is "fifty-five million, seven hundred seventy-two thousand, two hundred seventeen".