25778157191 has 4 divisors (see below), whose sum is σ = 25797942192. Its totient is φ = 25758372192.

The previous prime is 25778157157. The next prime is 25778157239. The reversal of 25778157191 is 19175187752.

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

It is a cyclic number.

It is not a de Polignac number, because 25778157191 - 2⁶ = 25778157127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25778157151) 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, 9890546 + ... + 9893151.

It is an arithmetic number, because the mean of its divisors is an integer number (6449485548).

Almost surely, 2^25778157191 is an apocalyptic number.

25778157191 is a deficient number, since it is larger than the sum of its proper divisors (19785001).

25778157191 is a wasteful number, since it uses less digits than its factorization.

25778157191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19785000.

The product of its digits is 1234800, while the sum is 53.

The spelling of 25778157191 in words is "twenty-five billion, seven hundred seventy-eight million, one hundred fifty-seven thousand, one hundred ninety-one".