25721451 has 24 divisors (see below), whose sum is σ = 42981120. Its totient is φ = 14517936.

The previous prime is 25721447. The next prime is 25721461. The reversal of 25721451 is 15412752.

It is not a de Polignac number, because 25721451 - 2² = 25721447 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25721431) 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 23 ways as a sum of consecutive naturals, for example, 2770 + ... + 7688.

It is an arithmetic number, because the mean of its divisors is an integer number (1790880).

Almost surely, 2^25721451 is an apocalyptic number.

25721451 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

25721451 is a deficient number, since it is larger than the sum of its proper divisors (17259669).

25721451 is a wasteful number, since it uses less digits than its factorization.

25721451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5015 (or 5012 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 25721451 is about 5071.6319858602. The cubic root of 25721451 is about 295.1878569817.

The spelling of 25721451 in words is "twenty-five million, seven hundred twenty-one thousand, four hundred fifty-one".