22097781 has 6 divisors (see below), whose sum is σ = 31919030. Its totient is φ = 14731848.

The previous prime is 22097771. The next prime is 22097783. The reversal of 22097781 is 18779022.

It can be written as a sum of positive squares in only one way, i.e., 22043025 + 54756 = 4695^2 + 234^2 .

It is not a de Polignac number, because 22097781 - 2⁵ = 22097749 is a prime.

It is a super-2 number, since 2×22097781² = 976623850247922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22097783) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1227646 + ... + 1227663.

Almost surely, 2^22097781 is an apocalyptic number.

It is an amenable number.

22097781 is a deficient number, since it is larger than the sum of its proper divisors (9821249).

22097781 is a wasteful number, since it uses less digits than its factorization.

22097781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2455315 (or 2455312 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 22097781 is about 4700.8276930770. The cubic root of 22097781 is about 280.6184501690.

The spelling of 22097781 in words is "twenty-two million, ninety-seven thousand, seven hundred eighty-one".