391432320 has 96 divisors (see below), whose sum is σ = 1351684620. Its totient is φ = 104380416.

The previous prime is 391432277. The next prime is 391432333. The reversal of 391432320 is 23234193.

It is a happy number.

391432320 is a `hidden beast` number, since 391 + 43 + 232 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 340623936 + 50808384 = 18456^2 + 7128^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×391432320² = 306438522281164800, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28219 + ... + 39738.

Almost surely, 2^391432320 is an apocalyptic number.

391432320 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

391432320 is an abundant number, since it is smaller than the sum of its proper divisors (960252300).

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

391432320 is a wasteful number, since it uses less digits than its factorization.

391432320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67982 (or 67967 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 391432320 is about 19784.6485943016. The cubic root of 391432320 is about 731.5076865222.

The spelling of 391432320 in words is "three hundred ninety-one million, four hundred thirty-two thousand, three hundred twenty".