25550222021 has 2 divisors, whose sum is σ = 25550222022. Its totient is φ = 25550222020.

The previous prime is 25550222003. The next prime is 25550222023. The reversal of 25550222021 is 12022205552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25548505921 + 1716100 = 159839^2 + 1310^2 .

It is a cyclic number.

It is not a de Polignac number, because 25550222021 - 2²⁶ = 25483113157 is a prime.

Together with 25550222023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25550222023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12775111010 + 12775111011.

It is an arithmetic number, because the mean of its divisors is an integer number (12775111011).

Almost surely, 2^25550222021 is an apocalyptic number.

It is an amenable number.

25550222021 is a deficient number, since it is larger than the sum of its proper divisors (1).

25550222021 is an equidigital number, since it uses as much as digits as its factorization.

25550222021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4000, while the sum is 26.

Adding to 25550222021 its reverse (12022205552), we get a palindrome (37572427573).

The spelling of 25550222021 in words is "twenty-five billion, five hundred fifty million, two hundred twenty-two thousand, twenty-one".