51351665625 has 72 divisors (see below), whose sum is σ = 99844781400. Its totient is φ = 25280640000.

The previous prime is 51351665597. The next prime is 51351665627. The reversal of 51351665625 is 52656615315.

51351665625 is a `hidden beast` number, since 5 + 1 + 3 + 5 + 16 + 6 + 5 + 625 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 48694366224 + 2657299401 = 220668^2 + 51549^2 .

It is not a de Polignac number, because 51351665625 - 2¹¹ = 51351663577 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (51351665627) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 295401 + ... + 435849.

It is an arithmetic number, because the mean of its divisors is an integer number (1386733075).

Almost surely, 2^51351665625 is an apocalyptic number.

It is an amenable number.

51351665625 is a deficient number, since it is larger than the sum of its proper divisors (48493115775).

51351665625 is a wasteful number, since it uses less digits than its factorization.

51351665625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140493 (or 140470 counting only the distinct ones).

The product of its digits is 810000, while the sum is 45.

The spelling of 51351665625 in words is "fifty-one billion, three hundred fifty-one million, six hundred sixty-five thousand, six hundred twenty-five".