391037428656 has 600 divisors, whose sum is σ = 1354940421120. Its totient is φ = 106641142272.

The previous prime is 391037428637. The next prime is 391037428687. The reversal of 391037428656 is 656824730193.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 816361825 + ... + 816362303.

It is a 1-persistent number, because it is pandigital, but 2⋅391037428656 = 782074857312 is not.

Almost surely, 2^391037428656 is an apocalyptic number.

391037428656 is a gapful number since it is divisible by the number (36) 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 391037428656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (677470210560).

391037428656 is an abundant number, since it is smaller than the sum of its proper divisors (963902992464).

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

391037428656 is a wasteful number, since it uses less digits than its factorization.

391037428656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671 (or 627 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 54.

The spelling of 391037428656 in words is "three hundred ninety-one billion, thirty-seven million, four hundred twenty-eight thousand, six hundred fifty-six".