55631281 has 4 divisors (see below), whose sum is σ = 55807092. Its totient is φ = 55455472.

The previous prime is 55631263. The next prime is 55631287. The reversal of 55631281 is 18213655.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18213655 = 5 ⋅3642731.

It can be written as a sum of positive squares in 2 ways, for example, as 8503056 + 47128225 = 2916^2 + 6865^2 .

It is a cyclic number.

It is not a de Polignac number, because 55631281 - 2⁵ = 55631249 is a prime.

It is a super-2 number, since 2×55631281² = 6189678851401922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55631287) 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, 87430 + ... + 88063.

It is an arithmetic number, because the mean of its divisors is an integer number (13951773).

Almost surely, 2^55631281 is an apocalyptic number.

It is an amenable number.

55631281 is a deficient number, since it is larger than the sum of its proper divisors (175811).

55631281 is a wasteful number, since it uses less digits than its factorization.

55631281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175810.

The product of its digits is 7200, while the sum is 31.

The square root of 55631281 is about 7458.6380123988. The cubic root of 55631281 is about 381.7447034634.

The spelling of 55631281 in words is "fifty-five million, six hundred thirty-one thousand, two hundred eighty-one".