25721993264 has 80 divisors (see below), whose sum is σ = 54876800160. Its totient is φ = 11582638080.

The previous prime is 25721993263. The next prime is 25721993287. The reversal of 25721993264 is 46239912752.

It is a happy number.

It is a super-2 number, since 2×25721993264² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25721993263) 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, 10747652 + ... + 10750044.

It is an arithmetic number, because the mean of its divisors is an integer number (685960002).

Almost surely, 2^25721993264 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 25721993264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27438400080).

25721993264 is an abundant number, since it is smaller than the sum of its proper divisors (29154806896).

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

25721993264 is a wasteful number, since it uses less digits than its factorization.

25721993264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2958 (or 2952 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 50.

The spelling of 25721993264 in words is "twenty-five billion, seven hundred twenty-one million, nine hundred ninety-three thousand, two hundred sixty-four".