51321242531 has 4 divisors (see below), whose sum is σ = 55269030432. Its totient is φ = 47373454632.

The previous prime is 51321242527. The next prime is 51321242561. The reversal of 51321242531 is 13524212315.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51321242531 - 2² = 51321242527 is a prime.

It is a super-2 number, since 2×51321242531² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51321242494 and 51321242503.

It is not an unprimeable number, because it can be changed into a prime (51321242561) 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, 1973893931 + ... + 1973893956.

It is an arithmetic number, because the mean of its divisors is an integer number (13817257608).

Almost surely, 2^51321242531 is an apocalyptic number.

51321242531 is a deficient number, since it is larger than the sum of its proper divisors (3947787901).

51321242531 is a wasteful number, since it uses less digits than its factorization.

51321242531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3947787900.

The product of its digits is 7200, while the sum is 29.

Adding to 51321242531 its reverse (13524212315), we get a palindrome (64845454846).

The spelling of 51321242531 in words is "fifty-one billion, three hundred twenty-one million, two hundred forty-two thousand, five hundred thirty-one".