55231551 has 20 divisors (see below), whose sum is σ = 84523824. Its totient is φ = 35920800.

The previous prime is 55231549. The next prime is 55231559. The reversal of 55231551 is 15513255.

It is not a de Polignac number, because 55231551 - 2¹ = 55231549 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55231559) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4995 + ... + 11636.

Almost surely, 2^55231551 is an apocalyptic number.

55231551 is a deficient number, since it is larger than the sum of its proper divisors (29292273).

55231551 is a wasteful number, since it uses less digits than its factorization.

55231551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16684 (or 16675 counting only the distinct ones).

The product of its digits is 3750, while the sum is 27.

The square root of 55231551 is about 7431.7932560049. The cubic root of 55231551 is about 380.8281821843.

The spelling of 55231551 in words is "fifty-five million, two hundred thirty-one thousand, five hundred fifty-one".