55631217 has 4 divisors (see below), whose sum is σ = 74174960. Its totient is φ = 37087476.

The previous prime is 55631209. The next prime is 55631237. The reversal of 55631217 is 71213655.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 55631217 - 2³ = 55631209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55631237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9271867 + ... + 9271872.

It is an arithmetic number, because the mean of its divisors is an integer number (18543740).

Almost surely, 2^55631217 is an apocalyptic number.

It is an amenable number.

55631217 is a deficient number, since it is larger than the sum of its proper divisors (18543743).

55631217 is a wasteful number, since it uses less digits than its factorization.

55631217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18543742.

The product of its digits is 6300, while the sum is 30.

The square root of 55631217 is about 7458.6337220700. The cubic root of 55631217 is about 381.7445570729.

The spelling of 55631217 in words is "fifty-five million, six hundred thirty-one thousand, two hundred seventeen".