36639440640 has 576 divisors, whose sum is σ = 146461593600. Its totient is φ = 8592998400.

The previous prime is 36639440627. The next prime is 36639440659. The reversal of 36639440640 is 4604493663.

36639440640 is a `hidden beast` number, since 3 + 6 + 639 + 4 + 4 + 0 + 6 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a super-2 number, since 2×36639440640² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11783406 + ... + 11786514.

It is an arithmetic number, because the mean of its divisors is an integer number (254273600).

Almost surely, 2^36639440640 is an apocalyptic number.

36639440640 is a gapful number since it is divisible by the number (30) 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 36639440640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73230796800).

36639440640 is an abundant number, since it is smaller than the sum of its proper divisors (109822152960).

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

36639440640 is a wasteful number, since it uses less digits than its factorization.

36639440640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3181 (or 3161 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 45.

The spelling of 36639440640 in words is "thirty-six billion, six hundred thirty-nine million, four hundred forty thousand, six hundred forty".