521723149 has 16 divisors (see below), whose sum is σ = 581022720. Its totient is φ = 466202880.

The previous prime is 521723141. The next prime is 521723201. The reversal of 521723149 is 941327125.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 521723149 - 2³ = 521723141 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 (521723141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18592 + ... + 37270.

It is an arithmetic number, because the mean of its divisors is an integer number (36313920).

Almost surely, 2^521723149 is an apocalyptic number.

It is an amenable number.

521723149 is a deficient number, since it is larger than the sum of its proper divisors (59299571).

521723149 is a wasteful number, since it uses less digits than its factorization.

521723149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18780.

The product of its digits is 15120, while the sum is 34.

The square root of 521723149 is about 22841.2597945035. The cubic root of 521723149 is about 805.0324171969.

The spelling of 521723149 in words is "five hundred twenty-one million, seven hundred twenty-three thousand, one hundred forty-nine".