25491720 has 64 divisors (see below), whose sum is σ = 77472000. Its totient is φ = 6709248.

The previous prime is 25491689. The next prime is 25491731. The reversal of 25491720 is 2719452.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8136 + ... + 10824.

It is an arithmetic number, because the mean of its divisors is an integer number (1210500).

Almost surely, 2^25491720 is an apocalyptic number.

25491720 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 25491720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38736000).

25491720 is an abundant number, since it is smaller than the sum of its proper divisors (51980280).

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

25491720 is a wasteful number, since it uses less digits than its factorization.

25491720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2782 (or 2778 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 25491720 is about 5048.9325604528. The cubic root of 25491720 is about 294.3064046066.

The spelling of 25491720 in words is "twenty-five million, four hundred ninety-one thousand, seven hundred twenty".