252135621 has 6 divisors (see below), whose sum is σ = 364195910. Its totient is φ = 168090408.

The previous prime is 252135613. The next prime is 252135629. The reversal of 252135621 is 126531252.

It is a happy number.

252135621 is a `hidden beast` number, since 2 + 5 + 2 + 1 + 35 + 621 = 666.

It is an interprime number because it is at equal distance from previous prime (252135613) and next prime (252135629).

It can be written as a sum of positive squares in only one way, i.e., 137945025 + 114190596 = 11745^2 + 10686^2 .

It is not a de Polignac number, because 252135621 - 2³ = 252135613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (252135629) 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 5 ways as a sum of consecutive naturals, for example, 14007526 + ... + 14007543.

Almost surely, 2^252135621 is an apocalyptic number.

It is an amenable number.

252135621 is a deficient number, since it is larger than the sum of its proper divisors (112060289).

252135621 is a wasteful number, since it uses less digits than its factorization.

252135621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28015075 (or 28015072 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 252135621 is about 15878.7789517960. The cubic root of 252135621 is about 631.7492504240.

Adding to 252135621 its reverse (126531252), we get a palindrome (378666873).

The spelling of 252135621 in words is "two hundred fifty-two million, one hundred thirty-five thousand, six hundred twenty-one".