51645431 has 2 divisors, whose sum is σ = 51645432. Its totient is φ = 51645430.

The previous prime is 51645427. The next prime is 51645469. The reversal of 51645431 is 13454615.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51645431 - 2² = 51645427 is a prime.

It is a super-2 number, since 2×51645431² = 5334501086351522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 51645394 and 51645403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51645421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25822715 + 25822716.

It is an arithmetic number, because the mean of its divisors is an integer number (25822716).

Almost surely, 2^51645431 is an apocalyptic number.

51645431 is a deficient number, since it is larger than the sum of its proper divisors (1).

51645431 is an equidigital number, since it uses as much as digits as its factorization.

51645431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7200, while the sum is 29.

The square root of 51645431 is about 7186.4755617757. The cubic root of 51645431 is about 372.4008258121.

The spelling of 51645431 in words is "fifty-one million, six hundred forty-five thousand, four hundred thirty-one".