390642780 has 192 divisors, whose sum is σ = 1255919616. Its totient is φ = 89856000.

The previous prime is 390642773. The next prime is 390642809. The reversal of 390642780 is 87246093.

It is a super-2 number, since 2×390642780² = 305203563132256800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1247904 + ... + 1248216.

It is an arithmetic number, because the mean of its divisors is an integer number (6541248).

Almost surely, 2^390642780 is an apocalyptic number.

390642780 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 390642780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (627959808).

390642780 is an abundant number, since it is smaller than the sum of its proper divisors (865276836).

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

390642780 is a wasteful number, since it uses less digits than its factorization.

390642780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428 (or 426 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 390642780 is about 19764.6851733085. The cubic root of 390642780 is about 731.0155253792.

The spelling of 390642780 in words is "three hundred ninety million, six hundred forty-two thousand, seven hundred eighty".