25710721920 has 640 divisors, whose sum is σ = 99919844640. Its totient is φ = 6288482304.

The previous prime is 25710721889. The next prime is 25710721957. The reversal of 25710721920 is 2912701752.

25710721920 is a `hidden beast` number, since 2 + 571 + 0 + 72 + 19 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a super-2 number, since 2×25710721920² (a number of 22 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 163762482 + ... + 163762638.

Almost surely, 2^25710721920 is an apocalyptic number.

25710721920 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 25710721920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49959922320).

25710721920 is an abundant number, since it is smaller than the sum of its proper divisors (74209122720).

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

25710721920 is an frugal number, since it uses more digits than its factorization.

25710721920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 36.

The spelling of 25710721920 in words is "twenty-five billion, seven hundred ten million, seven hundred twenty-one thousand, nine hundred twenty".