2639712640 has 64 divisors (see below), whose sum is σ = 6328692000. Its totient is φ = 1052852224.

The previous prime is 2639712629. The next prime is 2639712643. The reversal of 2639712640 is 462179362.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 2639712593 and 2639712602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2639712643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 224016 + ... + 235504.

Almost surely, 2^2639712640 is an apocalyptic number.

2639712640 is a gapful number since it is divisible by the number (20) 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 2639712640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3164346000).

2639712640 is an abundant number, since it is smaller than the sum of its proper divisors (3688979360).

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

2639712640 is a wasteful number, since it uses less digits than its factorization.

2639712640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11867 (or 11855 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 40.

The square root of 2639712640 is about 51378.1338703538. The cubic root of 2639712640 is about 1382.0344982428.

2639712640 divided by its sum of digits (40) gives a triangular number (65992816 = T₁₁₄₈₈).

The spelling of 2639712640 in words is "two billion, six hundred thirty-nine million, seven hundred twelve thousand, six hundred forty".