51353786521 has 4 divisors (see below), whose sum is σ = 53586559872. Its totient is φ = 49121013172.

The previous prime is 51353786503. The next prime is 51353786527. The reversal of 51353786521 is 12568735315.

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 51353786521 - 2⁵ = 51353786489 is a prime.

It is a super-2 number, since 2×51353786521² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51353786527) 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, 1116386641 + ... + 1116386686.

It is an arithmetic number, because the mean of its divisors is an integer number (13396639968).

Almost surely, 2^51353786521 is an apocalyptic number.

It is an amenable number.

51353786521 is a deficient number, since it is larger than the sum of its proper divisors (2232773351).

51353786521 is a wasteful number, since it uses less digits than its factorization.

51353786521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2232773350.

The product of its digits is 756000, while the sum is 46.

The spelling of 51353786521 in words is "fifty-one billion, three hundred fifty-three million, seven hundred eighty-six thousand, five hundred twenty-one".