253891621 has 4 divisors (see below), whose sum is σ = 254599200. Its totient is φ = 253184044.

The previous prime is 253891597. The next prime is 253891637. The reversal of 253891621 is 126198352.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 253891621 - 2⁹ = 253891109 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 (253891021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353251 + ... + 353968.

It is an arithmetic number, because the mean of its divisors is an integer number (63649800).

Almost surely, 2^253891621 is an apocalyptic number.

It is an amenable number.

253891621 is a deficient number, since it is larger than the sum of its proper divisors (707579).

253891621 is an equidigital number, since it uses as much as digits as its factorization.

253891621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707578.

The product of its digits is 25920, while the sum is 37.

The square root of 253891621 is about 15933.9769360948. The cubic root of 253891621 is about 633.2124659160.

The spelling of 253891621 in words is "two hundred fifty-three million, eight hundred ninety-one thousand, six hundred twenty-one".