252655721 has 8 divisors (see below), whose sum is σ = 260836104. Its totient is φ = 244546560.

The previous prime is 252655709. The next prime is 252655763. The reversal of 252655721 is 127556252.

It can be written as a sum of positive squares in 4 ways, for example, as 103815721 + 148840000 = 10189^2 + 12200^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 252655721 - 2²² = 248461417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (252655771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10550 + ... + 24831.

It is an arithmetic number, because the mean of its divisors is an integer number (32604513).

Almost surely, 2^252655721 is an apocalyptic number.

It is an amenable number.

252655721 is a deficient number, since it is larger than the sum of its proper divisors (8180383).

252655721 is a wasteful number, since it uses less digits than its factorization.

252655721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35611.

The product of its digits is 42000, while the sum is 35.

The square root of 252655721 is about 15895.1477187222. The cubic root of 252655721 is about 632.1833383937.

The spelling of 252655721 in words is "two hundred fifty-two million, six hundred fifty-five thousand, seven hundred twenty-one".