2661252864 has 72 divisors (see below), whose sum is σ = 7188666240. Its totient is φ = 873827328.

The previous prime is 2661252827. The next prime is 2661252871. The reversal of 2661252864 is 4682521662.

It is a happy number.

It is a super-2 number, since 2×2661252864² = 14164533612296404992, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25597 + ... + 77315.

Almost surely, 2^2661252864 is an apocalyptic number.

2661252864 is a gapful number since it is divisible by the number (24) 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 2661252864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3594333120).

2661252864 is an abundant number, since it is smaller than the sum of its proper divisors (4527413376).

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

2661252864 is an equidigital number, since it uses as much as digits as its factorization.

2661252864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51805 (or 51791 counting only the distinct ones).

The product of its digits is 276480, while the sum is 42.

The square root of 2661252864 is about 51587.3323985647. The cubic root of 2661252864 is about 1385.7834826455.

The spelling of 2661252864 in words is "two billion, six hundred sixty-one million, two hundred fifty-two thousand, eight hundred sixty-four".