3656447873640 has 256 divisors, whose sum is σ = 12476720044800. Its totient is φ = 951986552832.

The previous prime is 3656447873627. The next prime is 3656447873641. The reversal of 3656447873640 is 463787446563.

3656447873640 is a `hidden beast` number, since 3 + 6 + 56 + 4 + 478 + 73 + 6 + 40 = 666.

It is a super-2 number, since 2×3656447873640² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3656447873641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 123376264 + ... + 123405896.

It is an arithmetic number, because the mean of its divisors is an integer number (48737187675).

Almost surely, 2^{3656447873640} is an apocalyptic number.

3656447873640 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 3656447873640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6238360022400).

3656447873640 is an abundant number, since it is smaller than the sum of its proper divisors (8820272171160).

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

3656447873640 is a wasteful number, since it uses less digits than its factorization.

3656447873640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32353 (or 32343 counting only the distinct ones).

The product of its (nonzero) digits is 243855360, while the sum is 63.

The spelling of 3656447873640 in words is "three trillion, six hundred fifty-six billion, four hundred forty-seven million, eight hundred seventy-three thousand, six hundred forty".