51387788929 has 4 divisors (see below), whose sum is σ = 51411659076. Its totient is φ = 51363918784.

The previous prime is 51387788927. The next prime is 51387788951. The reversal of 51387788929 is 92988778315.

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

It can be written as a sum of positive squares in 2 ways, for example, as 28409776704 + 22978012225 = 168552^2 + 151585^2 .

It is a cyclic number.

It is not a de Polignac number, because 51387788929 - 2¹ = 51387788927 is a prime.

It is a super-2 number, since 2×51387788929² (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 (51387788927) 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, 11931844 + ... + 11936149.

It is an arithmetic number, because the mean of its divisors is an integer number (12852914769).

Almost surely, 2^51387788929 is an apocalyptic number.

It is an amenable number.

51387788929 is a deficient number, since it is larger than the sum of its proper divisors (23870147).

51387788929 is a wasteful number, since it uses less digits than its factorization.

51387788929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23870146.

The product of its digits is 60963840, while the sum is 67.

The spelling of 51387788929 in words is "fifty-one billion, three hundred eighty-seven million, seven hundred eighty-eight thousand, nine hundred twenty-nine".