51331551 has 32 divisors (see below), whose sum is σ = 75271680. Its totient is φ = 30987264.

The previous prime is 51331513. The next prime is 51331573. The reversal of 51331551 is 15513315.

It is not a de Polignac number, because 51331551 - 2¹⁰ = 51330527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51331591) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 195046 + ... + 195308.

It is an arithmetic number, because the mean of its divisors is an integer number (2352240).

Almost surely, 2^51331551 is an apocalyptic number.

51331551 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

51331551 is a deficient number, since it is larger than the sum of its proper divisors (23940129).

51331551 is a wasteful number, since it uses less digits than its factorization.

51331551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415.

The product of its digits is 1125, while the sum is 24.

The square root of 51331551 is about 7164.6040365117. The cubic root of 51331551 is about 371.6448584825.

Adding to 51331551 its reverse (15513315), we get a palindrome (66844866).

The spelling of 51331551 in words is "fifty-one million, three hundred thirty-one thousand, five hundred fifty-one".