391992120 has 288 divisors, whose sum is σ = 1464512400. Its totient is φ = 90574848.

The previous prime is 391992113. The next prime is 391992121. The reversal of 391992120 is 21299193.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391992121) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1034091 + ... + 1034469.

Almost surely, 2^391992120 is an apocalyptic number.

391992120 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 391992120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (732256200).

391992120 is an abundant number, since it is smaller than the sum of its proper divisors (1072520280).

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

391992120 is a wasteful number, since it uses less digits than its factorization.

391992120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439 (or 419 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 36.

The square root of 391992120 is about 19798.7908721720. The cubic root of 391992120 is about 731.8562380042.

The spelling of 391992120 in words is "three hundred ninety-one million, nine hundred ninety-two thousand, one hundred twenty".