51521739 has 8 divisors (see below), whose sum is σ = 68729232. Its totient is φ = 34331040.

The previous prime is 51521737. The next prime is 51521753. The reversal of 51521739 is 93712515.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51521739 - 2¹ = 51521737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51521737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8169 + ... + 13029.

It is an arithmetic number, because the mean of its divisors is an integer number (8591154).

Almost surely, 2^51521739 is an apocalyptic number.

51521739 is a deficient number, since it is larger than the sum of its proper divisors (17207493).

51521739 is a wasteful number, since it uses less digits than its factorization.

51521739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8397.

The product of its digits is 9450, while the sum is 33.

The square root of 51521739 is about 7177.8645152998. The cubic root of 51521739 is about 372.1032852873.

The spelling of 51521739 in words is "fifty-one million, five hundred twenty-one thousand, seven hundred thirty-nine".