253871621 has 4 divisors (see below), whose sum is σ = 255187212. Its totient is φ = 252556032.

The previous prime is 253871609. The next prime is 253871627. The reversal of 253871621 is 126178352.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 51122500 + 202749121 = 7150^2 + 14239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-253871621 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 (253871627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 657506 + ... + 657891.

It is an arithmetic number, because the mean of its divisors is an integer number (63796803).

Almost surely, 2^253871621 is an apocalyptic number.

It is an amenable number.

253871621 is a deficient number, since it is larger than the sum of its proper divisors (1315591).

253871621 is a wasteful number, since it uses less digits than its factorization.

253871621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1315590.

The product of its digits is 20160, while the sum is 35.

The square root of 253871621 is about 15933.3493340226. The cubic root of 253871621 is about 633.1958386351.

The spelling of 253871621 in words is "two hundred fifty-three million, eight hundred seventy-one thousand, six hundred twenty-one".