646261604464 has 120 divisors (see below), whose sum is σ = 1542994017360. Its totient is φ = 260719699968.

The previous prime is 646261604423. The next prime is 646261604491. The reversal of 646261604464 is 464406162646.

It is a super-2 number, since 2×646261604464² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2200504 + ... + 2476840.

It is an arithmetic number, because the mean of its divisors is an integer number (12858283478).

Almost surely, 2^646261604464 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 646261604464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (771497008680).

646261604464 is an abundant number, since it is smaller than the sum of its proper divisors (896732412896).

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

646261604464 is a wasteful number, since it uses less digits than its factorization.

646261604464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276535 (or 276522 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 49.

The spelling of 646261604464 in words is "six hundred forty-six billion, two hundred sixty-one million, six hundred four thousand, four hundred sixty-four".