253521404 has 24 divisors (see below), whose sum is σ = 450914688. Its totient is φ = 124696880.

The previous prime is 253521403. The next prime is 253521439. The reversal of 253521404 is 404125352.

It is a happy number.

It is a super-2 number, since 2×253521404² = 128546204572262432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (253521403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193319 + ... + 194625.

It is an arithmetic number, because the mean of its divisors is an integer number (18788112).

Almost surely, 2^253521404 is an apocalyptic number.

It is an amenable number.

253521404 is a deficient number, since it is larger than the sum of its proper divisors (197393284).

253521404 is a wasteful number, since it uses less digits than its factorization.

253521404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2065 (or 2063 counting only the distinct ones).

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

The square root of 253521404 is about 15922.3554790113. The cubic root of 253521404 is about 632.9045391777.

Adding to 253521404 its reverse (404125352), we get a palindrome (657646756).

The spelling of 253521404 in words is "two hundred fifty-three million, five hundred twenty-one thousand, four hundred four".