390725640 has 128 divisors (see below), whose sum is σ = 1307548800. Its totient is φ = 103783680.

The previous prime is 390725639. The next prime is 390725653. The reversal of 390725640 is 46527093.

390725640 is a `hidden beast` number, since 3 + 9 + 0 + 7 + 2 + 5 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 390725595 and 390725604.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 356934 + ... + 358026.

It is an arithmetic number, because the mean of its divisors is an integer number (10215225).

Almost surely, 2^390725640 is an apocalyptic number.

390725640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 390725640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (653774400).

390725640 is an abundant number, since it is smaller than the sum of its proper divisors (916823160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

390725640 is a wasteful number, since it uses less digits than its factorization.

390725640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1444 (or 1434 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The square root of 390725640 is about 19766.7812250756. The cubic root of 390725640 is about 731.0672074336.

The spelling of 390725640 in words is "three hundred ninety million, seven hundred twenty-five thousand, six hundred forty".