381772521 has 45 divisors (see below), whose sum is σ = 621266151. Its totient is φ = 233530128.

The previous prime is 381772513. The next prime is 381772537. The reversal of 381772521 is 125277183.

The square root of 381772521 is 19539.

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., 56475225 + 325297296 = 7515^2 + 18036^2 .

It is not a de Polignac number, because 381772521 - 2³ = 381772513 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (381772571) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 2285980 + ... + 2286146.

Almost surely, 2^381772521 is an apocalyptic number.

381772521 is the 19539-th square number.

381772521 is the 9770-th centered octagonal number.

It is an amenable number.

381772521 is a deficient number, since it is larger than the sum of its proper divisors (239493630).

381772521 is an equidigital number, since it uses as much as digits as its factorization.

381772521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372 (or 183 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The cubic root of 381772521 is about 725.4400949049.

Multiplying 381772521 by its sum of digits (36), we get a square (13743810756 = 117234²).

The spelling of 381772521 in words is "three hundred eighty-one million, seven hundred seventy-two thousand, five hundred twenty-one".