25721790 has 32 divisors (see below), whose sum is σ = 61865856. Its totient is φ = 6844320.

The previous prime is 25721789. The next prime is 25721791. The reversal of 25721790 is 9712752.

It is an interprime number because it is at equal distance from previous prime (25721789) and next prime (25721791).

It is a super-2 number, since 2×25721790² = 1323220961608200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25721791) 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, 26005 + ... + 26975.

It is an arithmetic number, because the mean of its divisors is an integer number (1933308).

Almost surely, 2^25721790 is an apocalyptic number.

25721790 is an abundant number, since it is smaller than the sum of its proper divisors (36144066).

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

25721790 is a wasteful number, since it uses less digits than its factorization.

25721790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1864.

The product of its (nonzero) digits is 8820, while the sum is 33.

The square root of 25721790 is about 5071.6654069447. The cubic root of 25721790 is about 295.1891538013.

The spelling of 25721790 in words is "twenty-five million, seven hundred twenty-one thousand, seven hundred ninety".