51722665 has 8 divisors (see below), whose sum is σ = 62116488. Its totient is φ = 41345280.

The previous prime is 51722639. The next prime is 51722677. The reversal of 51722665 is 56622715.

51722665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 6456681 + 45265984 = 2541^2 + 6728^2 .

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

It is not a de Polignac number, because 51722665 - 2⁷ = 51722537 is a prime.

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 51722665.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 4435 + ... + 11095.

It is an arithmetic number, because the mean of its divisors is an integer number (7764561).

Almost surely, 2^51722665 is an apocalyptic number.

It is an amenable number.

51722665 is a deficient number, since it is larger than the sum of its proper divisors (10393823).

51722665 is a wasteful number, since it uses less digits than its factorization.

51722665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8219.

The product of its digits is 25200, while the sum is 34.

The square root of 51722665 is about 7191.8471201771. The cubic root of 51722665 is about 372.5863709752.

It can be divided in two parts, 5 and 1722665, that multiplied together give a triangular number (8613325 = T₄₁₅₀).

The spelling of 51722665 in words is "fifty-one million, seven hundred twenty-two thousand, six hundred sixty-five".