64491001632 has 96 divisors (see below), whose sum is σ = 188303572800. Its totient is φ = 21473593344.

The previous prime is 64491001609. The next prime is 64491001651. The reversal of 64491001632 is 23610019446.

64491001632 is a `hidden beast` number, since 6 + 4 + 4 + 9 + 10 + 0 + 1 + 632 = 666.

64491001632 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 762483 + ... + 842829.

It is an arithmetic number, because the mean of its divisors is an integer number (1961495550).

Almost surely, 2^64491001632 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 64491001632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94151786400).

64491001632 is an abundant number, since it is smaller than the sum of its proper divisors (123812571168).

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

64491001632 is a wasteful number, since it uses less digits than its factorization.

64491001632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81295 (or 81281 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The spelling of 64491001632 in words is "sixty-four billion, four hundred ninety-one million, one thousand, six hundred thirty-two".