320400149521 has 9 divisors (see below), whose sum is σ = 323015323899. Its totient is φ = 317805992784.

The previous prime is 320400149519. The next prime is 320400149539. The reversal of 320400149521 is 125941004023.

The square root of 320400149521 is 566039.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 225003179025 + 95396970496 = 474345^2 + 308864^2 .

It is not a de Polignac number, because 320400149521 - 2¹ = 320400149519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (320400149501) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 71884725 + ... + 71889181.

Almost surely, 2^320400149521 is an apocalyptic number.

320400149521 is the 566039-th square number.

320400149521 is the 283020-th centered octagonal number.

It is an amenable number.

320400149521 is a deficient number, since it is larger than the sum of its proper divisors (2615174378).

320400149521 is an frugal number, since it uses more digits than its factorization.

320400149521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9168 (or 4584 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The spelling of 320400149521 in words is "three hundred twenty billion, four hundred million, one hundred forty-nine thousand, five hundred twenty-one".