51388252521 has 4 divisors (see below), whose sum is σ = 68517670032. Its totient is φ = 34258835012.

The previous prime is 51388252507. The next prime is 51388252523. The reversal of 51388252521 is 12525288315.

It is a happy number.

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 51388252521 - 2⁹ = 51388252009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51388252523) 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, 8564708751 + ... + 8564708756.

It is an arithmetic number, because the mean of its divisors is an integer number (17129417508).

Almost surely, 2^51388252521 is an apocalyptic number.

It is an amenable number.

51388252521 is a deficient number, since it is larger than the sum of its proper divisors (17129417511).

51388252521 is a wasteful number, since it uses less digits than its factorization.

51388252521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17129417510.

The product of its digits is 192000, while the sum is 42.

The spelling of 51388252521 in words is "fifty-one billion, three hundred eighty-eight million, two hundred fifty-two thousand, five hundred twenty-one".