2561641632 has 288 divisors, whose sum is σ = 8325374400. Its totient is φ = 765642240.

The previous prime is 2561641603. The next prime is 2561641657. The reversal of 2561641632 is 2361461652.

2561641632 is a `hidden beast` number, since 2 + 5 + 6 + 1 + 641 + 6 + 3 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11186094 + ... + 11186322.

It is an arithmetic number, because the mean of its divisors is an integer number (28907550).

Almost surely, 2^2561641632 is an apocalyptic number.

2561641632 is a gapful number since it is divisible by the number (22) 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 2561641632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4162687200).

2561641632 is an abundant number, since it is smaller than the sum of its proper divisors (5763732768).

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

2561641632 is a wasteful number, since it uses less digits than its factorization.

2561641632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377 (or 352 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 2561641632 is about 50612.6627633836. The cubic root of 2561641632 is about 1368.2731064462.

The spelling of 2561641632 in words is "two billion, five hundred sixty-one million, six hundred forty-one thousand, six hundred thirty-two".