644566046004 has 36 divisors (see below), whose sum is σ = 1631438548740. Its totient is φ = 214575943680.

The previous prime is 644566045987. The next prime is 644566046023. The reversal of 644566046004 is 400640665446.

644566046004 is a `hidden beast` number, since 6 + 44 + 566 + 0 + 46 + 0 + 0 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 357915027600 + 286651018404 = 598260^2 + 535398^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×644566046004² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11613807 + ... + 11669174.

It is an arithmetic number, because the mean of its divisors is an integer number (45317737465).

Almost surely, 2^644566046004 is an apocalyptic number.

It is an amenable number.

644566046004 is an abundant number, since it is smaller than the sum of its proper divisors (986872502736).

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

644566046004 is a wasteful number, since it uses less digits than its factorization.

644566046004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23283760 (or 23283755 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 45.

The spelling of 644566046004 in words is "six hundred forty-four billion, five hundred sixty-six million, forty-six thousand, four".