2638648656 has 160 divisors (see below), whose sum is σ = 8775192320. Its totient is φ = 743510016.

The previous prime is 2638648651. The next prime is 2638648657. The reversal of 2638648656 is 6568468362.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2638648651) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 214776 + ... + 226728.

It is an arithmetic number, because the mean of its divisors is an integer number (54844952).

Almost surely, 2^2638648656 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 2638648656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4387596160).

2638648656 is an abundant number, since it is smaller than the sum of its proper divisors (6136543664).

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

2638648656 is a wasteful number, since it uses less digits than its factorization.

2638648656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12050 (or 12038 counting only the distinct ones).

The product of its digits is 9953280, while the sum is 54.

The square root of 2638648656 is about 51367.7783829513. The cubic root of 2638648656 is about 1381.8487886090.

The spelling of 2638648656 in words is "two billion, six hundred thirty-eight million, six hundred forty-eight thousand, six hundred fifty-six".