22025251981 has 2 divisors, whose sum is σ = 22025251982. Its totient is φ = 22025251980.

The previous prime is 22025251961. The next prime is 22025251999. The reversal of 22025251981 is 18915252022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21982806756 + 42445225 = 148266^2 + 6515^2 .

It is a cyclic number.

It is not a de Polignac number, because 22025251981 - 2¹⁵ = 22025219213 is a prime.

It is a super-2 number, since 2×22025251981² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 22025251981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22025251961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11012625990 + 11012625991.

It is an arithmetic number, because the mean of its divisors is an integer number (11012625991).

Almost surely, 2^22025251981 is an apocalyptic number.

It is an amenable number.

22025251981 is a deficient number, since it is larger than the sum of its proper divisors (1).

22025251981 is an equidigital number, since it uses as much as digits as its factorization.

22025251981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28800, while the sum is 37.

The spelling of 22025251981 in words is "twenty-two billion, twenty-five million, two hundred fifty-one thousand, nine hundred eighty-one".