394377720025 has 81 divisors (see below), whose sum is σ = 522266275479. Its totient is φ = 295408848000.

The previous prime is 394377720019. The next prime is 394377720031. The reversal of 394377720025 is 520027773493.

The square root of 394377720025 is 627995.

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

It is an interprime number because it is at equal distance from previous prime (394377720019) and next prime (394377720031).

It can be written as a sum of positive squares in 13 ways, for example, as 392774198089 + 1603521936 = 626717^2 + 40044^2 .

It is not a de Polignac number, because 394377720025 - 2³ = 394377720017 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 5554615740 + ... + 5554615810.

Almost surely, 2^394377720025 is an apocalyptic number.

394377720025 is the 627995-th square number.

394377720025 is the 313998-th centered octagonal number.

It is an amenable number.

394377720025 is a deficient number, since it is larger than the sum of its proper divisors (127888555454).

394377720025 is an frugal number, since it uses more digits than its factorization.

394377720025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 2222640, while the sum is 49.

Multiplying 394377720025 by its sum of digits (49), we get a square (19324508281225 = 4395965²).

The spelling of 394377720025 in words is "three hundred ninety-four billion, three hundred seventy-seven million, seven hundred twenty thousand, twenty-five".