25438165645 has 8 divisors (see below), whose sum is σ = 32321434104. Its totient is φ = 19153442304.

The previous prime is 25438165639. The next prime is 25438165651. The reversal of 25438165645 is 54656183452.

It is an interprime number because it is at equal distance from previous prime (25438165639) and next prime (25438165651).

It can be written as a sum of positive squares in 4 ways, for example, as 7090650436 + 18347515209 = 84206^2 + 135453^2 .

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 25438165645 - 2⁹ = 25438165133 is a prime.

It is a super-3 number, since 3×25438165645³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149636184 + ... + 149636353.

It is an arithmetic number, because the mean of its divisors is an integer number (4040179263).

Almost surely, 2^25438165645 is an apocalyptic number.

It is an amenable number.

25438165645 is a deficient number, since it is larger than the sum of its proper divisors (6883268459).

25438165645 is a wasteful number, since it uses less digits than its factorization.

25438165645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299272559.

The product of its digits is 3456000, while the sum is 49.

The spelling of 25438165645 in words is "twenty-five billion, four hundred thirty-eight million, one hundred sixty-five thousand, six hundred forty-five".