391968720 has 560 divisors, whose sum is σ = 1639395072. Its totient is φ = 85847040.

The previous prime is 391968719. The next prime is 391968749. The reversal of 391968720 is 27869193.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 8339737 + ... + 8339783.

Almost surely, 2^391968720 is an apocalyptic number.

391968720 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 391968720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (819697536).

391968720 is an abundant number, since it is smaller than the sum of its proper divisors (1247426352).

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

391968720 is a wasteful number, since it uses less digits than its factorization.

391968720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 391968720 is about 19798.1999181744. The cubic root of 391968720 is about 731.8416749761.

The spelling of 391968720 in words is "three hundred ninety-one million, nine hundred sixty-eight thousand, seven hundred twenty".