25649539 has 4 divisors (see below), whose sum is σ = 25665120. Its totient is φ = 25633960.

The previous prime is 25649501. The next prime is 25649557. The reversal of 25649539 is 93594652.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 25649539 - 2¹¹ = 25647491 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 25649495 and 25649504.

It is not an unprimeable number, because it can be changed into a prime (25649599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4984 + ... + 8725.

It is an arithmetic number, because the mean of its divisors is an integer number (6416280).

Almost surely, 2^25649539 is an apocalyptic number.

25649539 is a deficient number, since it is larger than the sum of its proper divisors (15581).

25649539 is a wasteful number, since it uses less digits than its factorization.

25649539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15580.

The product of its digits is 291600, while the sum is 43.

The square root of 25649539 is about 5064.5373924970. The cubic root of 25649539 is about 294.9125049340.

The spelling of 25649539 in words is "twenty-five million, six hundred forty-nine thousand, five hundred thirty-nine".