25161021065 has 4 divisors (see below), whose sum is σ = 30193225284. Its totient is φ = 20128816848.

The previous prime is 25161021029. The next prime is 25161021077. The reversal of 25161021065 is 56012016152.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8961840889 + 16199180176 = 94667^2 + 127276^2 .

It is a cyclic number.

It is not a de Polignac number, because 25161021065 - 2⁶ = 25161021001 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2516102102 + ... + 2516102111.

It is an arithmetic number, because the mean of its divisors is an integer number (7548306321).

Almost surely, 2^25161021065 is an apocalyptic number.

It is an amenable number.

25161021065 is a deficient number, since it is larger than the sum of its proper divisors (5032204219).

25161021065 is an equidigital number, since it uses as much as digits as its factorization.

25161021065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5032204218.

The product of its (nonzero) digits is 3600, while the sum is 29.

The spelling of 25161021065 in words is "twenty-five billion, one hundred sixty-one million, twenty-one thousand, sixty-five".