51581155 has 8 divisors (see below), whose sum is σ = 61963200. Its totient is φ = 41221056.

The previous prime is 51581149. The next prime is 51581171. The reversal of 51581155 is 55118515.

It is a happy number.

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 51581155 - 2⁷ = 51581027 is a prime.

It is a super-2 number, since 2×51581155² = 5321231102268050, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 231 + ... + 10159.

It is an arithmetic number, because the mean of its divisors is an integer number (7745400).

Almost surely, 2^51581155 is an apocalyptic number.

51581155 is a deficient number, since it is larger than the sum of its proper divisors (10382045).

51581155 is a wasteful number, since it uses less digits than its factorization.

51581155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10973.

The product of its digits is 5000, while the sum is 31.

The square root of 51581155 is about 7182.0021581729. The cubic root of 51581155 is about 372.2462695618.

Subtracting from 51581155 its sum of digits (31), we obtain a square (51581124 = 7182²).

The spelling of 51581155 in words is "fifty-one million, five hundred eighty-one thousand, one hundred fifty-five".