25416521 has 16 divisors (see below), whose sum is σ = 28670544. Its totient is φ = 22374144.

The previous prime is 25416493. The next prime is 25416527. The reversal of 25416521 is 12561452.

It can be written as a sum of positive squares in 8 ways, for example, as 2958400 + 22458121 = 1720^2 + 4739^2 .

It is a de Polignac number, because none of the positive numbers 2^k-25416521 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25416527) 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, 24995 + ... + 25991.

It is an arithmetic number, because the mean of its divisors is an integer number (1791909).

Almost surely, 2^25416521 is an apocalyptic number.

It is an amenable number.

25416521 is a deficient number, since it is larger than the sum of its proper divisors (3254023).

25416521 is a wasteful number, since it uses less digits than its factorization.

25416521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1100.

The product of its digits is 2400, while the sum is 26.

The square root of 25416521 is about 5041.4800406230. The cubic root of 25416521 is about 294.0167243328.

Adding to 25416521 its reverse (12561452), we get a palindrome (37977973).

The spelling of 25416521 in words is "twenty-five million, four hundred sixteen thousand, five hundred twenty-one".