521253491 has 4 divisors (see below), whose sum is σ = 568640184. Its totient is φ = 473866800.

The previous prime is 521253461. The next prime is 521253497. The reversal of 521253491 is 194352125.

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

It is not a de Polignac number, because 521253491 - 2⁶ = 521253427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521253497) 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, 23693330 + ... + 23693351.

It is an arithmetic number, because the mean of its divisors is an integer number (142160046).

Almost surely, 2^521253491 is an apocalyptic number.

521253491 is a deficient number, since it is larger than the sum of its proper divisors (47386693).

521253491 is a wasteful number, since it uses less digits than its factorization.

521253491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47386692.

The product of its digits is 10800, while the sum is 32.

The square root of 521253491 is about 22830.9765669364. The cubic root of 521253491 is about 804.7907798296.

The spelling of 521253491 in words is "five hundred twenty-one million, two hundred fifty-three thousand, four hundred ninety-one".