25977219661 has 4 divisors (see below), whose sum is σ = 26010228352. Its totient is φ = 25944210972.

The previous prime is 25977219601. The next prime is 25977219677. The reversal of 25977219661 is 16691277952.

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 25977219661 - 2¹⁹ = 25976695373 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 (25977219601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16503165 + ... + 16504738.

It is an arithmetic number, because the mean of its divisors is an integer number (6502557088).

Almost surely, 2^25977219661 is an apocalyptic number.

It is an amenable number.

25977219661 is a deficient number, since it is larger than the sum of its proper divisors (33008691).

25977219661 is an equidigital number, since it uses as much as digits as its factorization.

25977219661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33008690.

The product of its digits is 2857680, while the sum is 55.

The spelling of 25977219661 in words is "twenty-five billion, nine hundred seventy-seven million, two hundred nineteen thousand, six hundred sixty-one".