2505649664 has 160 divisors (see below), whose sum is σ = 5932614336. Its totient is φ = 1035141120.

The previous prime is 2505649661. The next prime is 2505649691. The reversal of 2505649664 is 4669465052.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2505649661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15959474 + ... + 15959630.

Almost surely, 2^2505649664 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 2505649664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2966307168).

2505649664 is an abundant number, since it is smaller than the sum of its proper divisors (3426964672).

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

2505649664 is an equidigital number, since it uses as much as digits as its factorization.

2505649664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316 (or 300 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 47.

The square root of 2505649664 is about 50056.4647573118. The cubic root of 2505649664 is about 1358.2304089561.

The spelling of 2505649664 in words is "two billion, five hundred five million, six hundred forty-nine thousand, six hundred sixty-four".