252161681 has 2 divisors, whose sum is σ = 252161682. Its totient is φ = 252161680.

The previous prime is 252161639. The next prime is 252161713. The reversal of 252161681 is 186161252.

It is an a-pointer prime, because the next prime (252161713) can be obtained adding 252161681 to its sum of digits (32).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 228493456 + 23668225 = 15116^2 + 4865^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-252161681 is a prime.

It is a super-2 number, since 2×252161681² = 127171026729491522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (252161621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 126080840 + 126080841.

It is an arithmetic number, because the mean of its divisors is an integer number (126080841).

Almost surely, 2^252161681 is an apocalyptic number.

It is an amenable number.

252161681 is a deficient number, since it is larger than the sum of its proper divisors (1).

252161681 is an equidigital number, since it uses as much as digits as its factorization.

252161681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5760, while the sum is 32.

The square root of 252161681 is about 15879.5995226580. The cubic root of 252161681 is about 631.7710149255.

The spelling of 252161681 in words is "two hundred fifty-two million, one hundred sixty-one thousand, six hundred eighty-one".