51139739 has 16 divisors (see below), whose sum is σ = 60579840. Its totient is φ = 42245280.

The previous prime is 51139717. The next prime is 51139747. The reversal of 51139739 is 93793115.

51139739 = T₁₆₉ + T₁₇₀ + ... + T₆₇₇.

It is a de Polignac number, because none of the positive numbers 2^k-51139739 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51139709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100217 + ... + 100725.

It is an arithmetic number, because the mean of its divisors is an integer number (3786240).

Almost surely, 2^51139739 is an apocalyptic number.

51139739 is a deficient number, since it is larger than the sum of its proper divisors (9440101).

51139739 is a wasteful number, since it uses less digits than its factorization.

51139739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010.

The product of its digits is 25515, while the sum is 38.

The square root of 51139739 is about 7151.2054228640. The cubic root of 51139739 is about 371.1813688806.

The spelling of 51139739 in words is "fifty-one million, one hundred thirty-nine thousand, seven hundred thirty-nine".