646840913487552 has 672 divisors, whose sum is σ = 2245897956556800. Its totient is φ = 173875305977856.

The previous prime is 646840913487541. The next prime is 646840913487619. The reversal of 646840913487552 is 255784319048646.

646840913487552 is a `hidden beast` number, since 6 + 4 + 6 + 8 + 4 + 0 + 91 + 3 + 487 + 5 + 52 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-2 number, since 2×646840913487552² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6719469373 + ... + 6719565635.

It is an arithmetic number, because the mean of its divisors is an integer number (3342110054400).

It is a 2-persistent number, because it is pandigital, and so is 2⋅646840913487552 = 1293681826975104, but 3⋅646840913487552 = 1940522740462656 is not.

Almost surely, 2^{646840913487552} 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 646840913487552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1122948978278400).

646840913487552 is an abundant number, since it is smaller than the sum of its proper divisors (1599057043069248).

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

646840913487552 is a wasteful number, since it uses less digits than its factorization.

646840913487552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96913 (or 96900 counting only the distinct ones).

The product of its (nonzero) digits is 1393459200, while the sum is 72.

The spelling of 646840913487552 in words is "six hundred forty-six trillion, eight hundred forty billion, nine hundred thirteen million, four hundred eighty-seven thousand, five hundred fifty-two".