25820692921 has 4 divisors (see below), whose sum is σ = 25875983952. Its totient is φ = 25765401892.

The previous prime is 25820692897. The next prime is 25820692927. The reversal of 25820692921 is 12929602852.

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 25820692921 - 2¹⁷ = 25820561849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25820692927) 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, 27644815 + ... + 27645748.

It is an arithmetic number, because the mean of its divisors is an integer number (6468995988).

Almost surely, 2^25820692921 is an apocalyptic number.

It is an amenable number.

25820692921 is a deficient number, since it is larger than the sum of its proper divisors (55291031).

25820692921 is an equidigital number, since it uses as much as digits as its factorization.

25820692921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55291030.

The product of its (nonzero) digits is 311040, while the sum is 46.

The spelling of 25820692921 in words is "twenty-five billion, eight hundred twenty million, six hundred ninety-two thousand, nine hundred twenty-one".