51699139 has 2 divisors, whose sum is σ = 51699140. Its totient is φ = 51699138.

The previous prime is 51699119. The next prime is 51699161. The reversal of 51699139 is 93199615.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51699139 - 2¹¹ = 51697091 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51699095 and 51699104.

It is not a weakly prime, because it can be changed into another prime (51699119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25849569 + 25849570.

It is an arithmetic number, because the mean of its divisors is an integer number (25849570).

Almost surely, 2^51699139 is an apocalyptic number.

51699139 is a deficient number, since it is larger than the sum of its proper divisors (1).

51699139 is an equidigital number, since it uses as much as digits as its factorization.

51699139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 65610, while the sum is 43.

The square root of 51699139 is about 7190.2113320820. The cubic root of 51699139 is about 372.5298722346.

The spelling of 51699139 in words is "fifty-one million, six hundred ninety-nine thousand, one hundred thirty-nine".