51531013 has 4 divisors (see below), whose sum is σ = 52404480. Its totient is φ = 50657548.

The previous prime is 51531001. The next prime is 51531049. The reversal of 51531013 is 31013515.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51531013 - 2¹⁷ = 51399941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51531113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 436645 + ... + 436762.

It is an arithmetic number, because the mean of its divisors is an integer number (13101120).

Almost surely, 2^51531013 is an apocalyptic number.

It is an amenable number.

51531013 is a deficient number, since it is larger than the sum of its proper divisors (873467).

51531013 is an equidigital number, since it uses as much as digits as its factorization.

51531013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 873466.

The product of its (nonzero) digits is 225, while the sum is 19.

The square root of 51531013 is about 7178.5105000968. The cubic root of 51531013 is about 372.1256103543.

Adding to 51531013 its reverse (31013515), we get a palindrome (82544528).

The spelling of 51531013 in words is "fifty-one million, five hundred thirty-one thousand, thirteen".