391726464 has 128 divisors (see below), whose sum is σ = 1079568000. Its totient is φ = 125767680.

The previous prime is 391726463. The next prime is 391726471. The reversal of 391726464 is 464627193.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391726463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2188327 + ... + 2188505.

It is an arithmetic number, because the mean of its divisors is an integer number (8434125).

Almost surely, 2^391726464 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 391726464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (539784000).

391726464 is an abundant number, since it is smaller than the sum of its proper divisors (687841536).

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

391726464 is a wasteful number, since it uses less digits than its factorization.

391726464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376 (or 364 counting only the distinct ones).

The product of its digits is 217728, while the sum is 42.

The square root of 391726464 is about 19792.0808405786. The cubic root of 391726464 is about 731.6908724881.

It can be divided in two parts, 3917 and 26464, that added together give a triangular number (30381 = T₂₄₆).

The spelling of 391726464 in words is "three hundred ninety-one million, seven hundred twenty-six thousand, four hundred sixty-four".