51601639 has 4 divisors (see below), whose sum is σ = 53266240. Its totient is φ = 49937040.

The previous prime is 51601633. The next prime is 51601651. The reversal of 51601639 is 93610615.

51601639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51601639 - 2¹¹ = 51599591 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 1664569 = 51601639 / (5 + 1 + 6 + 0 + 1 + 6 + 3 + 9).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51601639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51601633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 832254 + ... + 832315.

It is an arithmetic number, because the mean of its divisors is an integer number (13316560).

Almost surely, 2^51601639 is an apocalyptic number.

51601639 is a deficient number, since it is larger than the sum of its proper divisors (1664601).

51601639 is a wasteful number, since it uses less digits than its factorization.

51601639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1664600.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 51601639 is about 7183.4280813550. The cubic root of 51601639 is about 372.2955387406.

The spelling of 51601639 in words is "fifty-one million, six hundred one thousand, six hundred thirty-nine".