253421405 has 4 divisors (see below), whose sum is σ = 304105692. Its totient is φ = 202737120.

The previous prime is 253421353. The next prime is 253421407. The reversal of 253421405 is 504124352.

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 103652761 + 149768644 = 10181^2 + 12238^2 .

It is not a de Polignac number, because 253421405 - 2⁶ = 253421341 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 (253421407) 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, 25342136 + ... + 25342145.

It is an arithmetic number, because the mean of its divisors is an integer number (76026423).

Almost surely, 2^253421405 is an apocalyptic number.

It is an amenable number.

253421405 is a deficient number, since it is larger than the sum of its proper divisors (50684287).

253421405 is an equidigital number, since it uses as much as digits as its factorization.

253421405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50684286.

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 253421405 is about 15919.2149618001. The cubic root of 253421405 is about 632.8213139310.

Adding to 253421405 its reverse (504124352), we get a palindrome (757545757).

The spelling of 253421405 in words is "two hundred fifty-three million, four hundred twenty-one thousand, four hundred five".