391716864 has 448 divisors, whose sum is σ = 1509857280. Its totient is φ = 97320960.

The previous prime is 391716859. The next prime is 391716881. The reversal of 391716864 is 468617193.

391716864 = T₁₉₇ + T₁₉₈ + ... + T₁₃₃₀.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (448).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17031157 + ... + 17031179.

Almost surely, 2^391716864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391716864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (754928640).

391716864 is an abundant number, since it is smaller than the sum of its proper divisors (1118140416).

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

391716864 is a wasteful number, since it uses less digits than its factorization.

391716864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76 (or 46 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 391716864 is about 19791.8383178521. The cubic root of 391716864 is about 731.6848952817.

The spelling of 391716864 in words is "three hundred ninety-one million, seven hundred sixteen thousand, eight hundred sixty-four".