25158121217 has 4 divisors (see below), whose sum is σ = 26482232880. Its totient is φ = 23834009556.

The previous prime is 25158121189. The next prime is 25158121243. The reversal of 25158121217 is 71212185152.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25158121217 - 2⁸ = 25158120961 is a prime.

It is a super-2 number, since 2×25158121217² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25158121277) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 662055803 + ... + 662055840.

It is an arithmetic number, because the mean of its divisors is an integer number (6620558220).

Almost surely, 2^25158121217 is an apocalyptic number.

It is an amenable number.

25158121217 is a deficient number, since it is larger than the sum of its proper divisors (1324111663).

25158121217 is a wasteful number, since it uses less digits than its factorization.

25158121217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1324111662.

The product of its digits is 11200, while the sum is 35.

The spelling of 25158121217 in words is "twenty-five billion, one hundred fifty-eight million, one hundred twenty-one thousand, two hundred seventeen".