55515251 has 24 divisors (see below), whose sum is σ = 66600144. Its totient is φ = 45731840.

The previous prime is 55515241. The next prime is 55515253. The reversal of 55515251 is 15251555.

It is a de Polignac number, because none of the positive numbers 2^k-55515251 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55515253) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 157091 + ... + 157443.

It is an arithmetic number, because the mean of its divisors is an integer number (2775006).

Almost surely, 2^55515251 is an apocalyptic number.

55515251 is a deficient number, since it is larger than the sum of its proper divisors (11084893).

55515251 is a wasteful number, since it uses less digits than its factorization.

55515251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439 (or 410 counting only the distinct ones).

The product of its digits is 6250, while the sum is 29.

The square root of 55515251 is about 7450.8557226670. The cubic root of 55515251 is about 381.4791174634.

The spelling of 55515251 in words is "fifty-five million, five hundred fifteen thousand, two hundred fifty-one".