51231544 has 32 divisors (see below), whose sum is σ = 118228320. Its totient is φ = 20267136.

The previous prime is 51231491. The next prime is 51231547. The reversal of 51231544 is 44513215.

It is a happy number.

It is a super-2 number, since 2×51231544² = 5249342201247872, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51231547) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34459 + ... + 35914.

It is an arithmetic number, because the mean of its divisors is an integer number (3694635).

Almost surely, 2^51231544 is an apocalyptic number.

It is an amenable number.

51231544 is an abundant number, since it is smaller than the sum of its proper divisors (66996776).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51231544 is a wasteful number, since it uses less digits than its factorization.

51231544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70399 (or 70395 counting only the distinct ones).

The product of its digits is 2400, while the sum is 25.

The square root of 51231544 is about 7157.6213926136. The cubic root of 51231544 is about 371.4033484703.

Adding to 51231544 its reverse (44513215), we get a palindrome (95744759).

The spelling of 51231544 in words is "fifty-one million, two hundred thirty-one thousand, five hundred forty-four".