51643499 has 2 divisors, whose sum is σ = 51643500. Its totient is φ = 51643498.

The previous prime is 51643481. The next prime is 51643507. The reversal of 51643499 is 99434615.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51643499 - 2²⁴ = 34866283 is a prime.

It is not a weakly prime, because it can be changed into another prime (51643409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25821749 + 25821750.

It is an arithmetic number, because the mean of its divisors is an integer number (25821750).

Almost surely, 2^51643499 is an apocalyptic number.

51643499 is a deficient number, since it is larger than the sum of its proper divisors (1).

51643499 is an equidigital number, since it uses as much as digits as its factorization.

51643499 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 41.

The square root of 51643499 is about 7186.3411413598. The cubic root of 51643499 is about 372.3961820495.

The spelling of 51643499 in words is "fifty-one million, six hundred forty-three thousand, four hundred ninety-nine".