25434665221 has 4 divisors (see below), whose sum is σ = 29068188832. Its totient is φ = 21801141612.

The previous prime is 25434665213. The next prime is 25434665231. The reversal of 25434665221 is 12256643452.

It is a happy number.

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 25434665221 - 2³ = 25434665213 is a prime.

It is a super-3 number, since 3×25434665221³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25434665231) 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, 1816761795 + ... + 1816761808.

It is an arithmetic number, because the mean of its divisors is an integer number (7267047208).

Almost surely, 2^25434665221 is an apocalyptic number.

It is an amenable number.

25434665221 is a deficient number, since it is larger than the sum of its proper divisors (3633523611).

25434665221 is an equidigital number, since it uses as much as digits as its factorization.

25434665221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3633523610.

The product of its digits is 345600, while the sum is 40.

The spelling of 25434665221 in words is "twenty-five billion, four hundred thirty-four million, six hundred sixty-five thousand, two hundred twenty-one".