55405631 has 12 divisors (see below), whose sum is σ = 58288200. Its totient is φ = 52602480.

The previous prime is 55405619. The next prime is 55405633. The reversal of 55405631 is 13650455.

It is a de Polignac number, because none of the positive numbers 2^k-55405631 is a prime.

It is a super-2 number, since 2×55405631² = 6139567893016322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 55405594 and 55405603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55405633) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 146000 + ... + 146378.

It is an arithmetic number, because the mean of its divisors is an integer number (4857350).

Almost surely, 2^55405631 is an apocalyptic number.

55405631 is a deficient number, since it is larger than the sum of its proper divisors (2882569).

55405631 is an equidigital number, since it uses as much as digits as its factorization.

55405631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550 (or 479 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 29.

The square root of 55405631 is about 7443.4958856709. The cubic root of 55405631 is about 381.2278634106.

The spelling of 55405631 in words is "fifty-five million, four hundred five thousand, six hundred thirty-one".