25409721 has 12 divisors (see below), whose sum is σ = 34197008. Its totient is φ = 16782384.

The previous prime is 25409711. The next prime is 25409723. The reversal of 25409721 is 12790452.

It is not a de Polignac number, because 25409721 - 2¹³ = 25401529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25409723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 89646 + ... + 89928.

Almost surely, 2^25409721 is an apocalyptic number.

It is an amenable number.

25409721 is a deficient number, since it is larger than the sum of its proper divisors (8787287).

25409721 is an equidigital number, since it uses as much as digits as its factorization.

25409721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632 (or 459 counting only the distinct ones).

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

The square root of 25409721 is about 5040.8055903794. The cubic root of 25409721 is about 293.9905013360.

The spelling of 25409721 in words is "twenty-five million, four hundred nine thousand, seven hundred twenty-one".