55217831 has 8 divisors (see below), whose sum is σ = 55770624. Its totient is φ = 54667800.

The previous prime is 55217821. The next prime is 55217837. The reversal of 55217831 is 13871255.

55217831 = T₁₉₄ + T₁₉₅ + ... + T₆₉₆.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 55217831 - 2²² = 51023527 is a prime.

It is a super-2 number, since 2×55217831² = 6098017720689122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55217837) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75590 + ... + 76316.

It is an arithmetic number, because the mean of its divisors is an integer number (6971328).

Almost surely, 2^55217831 is an apocalyptic number.

55217831 is a deficient number, since it is larger than the sum of its proper divisors (552793).

55217831 is a wasteful number, since it uses less digits than its factorization.

55217831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1381.

The product of its digits is 8400, while the sum is 32.

The square root of 55217831 is about 7430.8701374738. The cubic root of 55217831 is about 380.7966458899.

The spelling of 55217831 in words is "fifty-five million, two hundred seventeen thousand, eight hundred thirty-one".