51685372451 has 4 divisors (see below), whose sum is σ = 51691362504. Its totient is φ = 51679382400.

The previous prime is 51685372441. The next prime is 51685372477. The reversal of 51685372451 is 15427358615.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15427358615 = 5 ⋅3085471723.

It is a cyclic number.

It is not a de Polignac number, because 51685372451 - 2¹⁴ = 51685356067 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51685372396 and 51685372405.

It is not an unprimeable number, because it can be changed into a prime (51685372411) 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, 2982065 + ... + 2999346.

It is an arithmetic number, because the mean of its divisors is an integer number (12922840626).

Almost surely, 2^51685372451 is an apocalyptic number.

51685372451 is a deficient number, since it is larger than the sum of its proper divisors (5990053).

51685372451 is an equidigital number, since it uses as much as digits as its factorization.

51685372451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5990052.

The product of its digits is 1008000, while the sum is 47.

The spelling of 51685372451 in words is "fifty-one billion, six hundred eighty-five million, three hundred seventy-two thousand, four hundred fifty-one".