391863420 has 240 divisors, whose sum is σ = 1383117120. Its totient is φ = 92150784.

The previous prime is 391863389. The next prime is 391863469. The reversal of 391863420 is 24368193.

391863420 is a `hidden beast` number, since 3 + 9 + 18 + 634 + 2 + 0 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 483976 + ... + 484784.

It is an arithmetic number, because the mean of its divisors is an integer number (5762988).

Almost surely, 2^391863420 is an apocalyptic number.

391863420 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 391863420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (691558560).

391863420 is an abundant number, since it is smaller than the sum of its proper divisors (991253700).

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

391863420 is a wasteful number, since it uses less digits than its factorization.

391863420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866 (or 855 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 391863420 is about 19795.5404068694. The cubic root of 391863420 is about 731.7761341763.

The spelling of 391863420 in words is "three hundred ninety-one million, eight hundred sixty-three thousand, four hundred twenty".