25105561 has 8 divisors (see below), whose sum is σ = 27969480. Its totient is φ = 22374912.

The previous prime is 25105547. The next prime is 25105579. The reversal of 25105561 is 16550152.

It can be written as a sum of positive squares in 4 ways, for example, as 553536 + 24552025 = 744^2 + 4955^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 25105561 - 2⁷ = 25105433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25105261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32920 + ... + 33673.

It is an arithmetic number, because the mean of its divisors is an integer number (3496185).

Almost surely, 2^25105561 is an apocalyptic number.

It is an amenable number.

25105561 is a deficient number, since it is larger than the sum of its proper divisors (2863919).

25105561 is a wasteful number, since it uses less digits than its factorization.

25105561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66635.

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 25105561 is about 5010.5449803390. The cubic root of 25105561 is about 292.8127455770.

The spelling of 25105561 in words is "twenty-five million, one hundred five thousand, five hundred sixty-one".