22664781 has 6 divisors (see below), whose sum is σ = 32738030. Its totient is φ = 15109848.

The previous prime is 22664779. The next prime is 22664783. The reversal of 22664781 is 18746622.

22664781 is a `hidden beast` number, since 2 + 2 + 6 + 647 + 8 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (22664779) and next prime (22664783).

It can be written as a sum of positive squares in only one way, i.e., 22610025 + 54756 = 4755^2 + 234^2 .

It is not a de Polignac number, because 22664781 - 2¹ = 22664779 is a prime.

It is a super-2 number, since 2×22664781² = 1027384595555922, 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 (22664783) 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, 1259146 + ... + 1259163.

Almost surely, 2^22664781 is an apocalyptic number.

It is an amenable number.

22664781 is a deficient number, since it is larger than the sum of its proper divisors (10073249).

22664781 is a wasteful number, since it uses less digits than its factorization.

22664781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2518315 (or 2518312 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 22664781 is about 4760.7542469655. The cubic root of 22664781 is about 282.9983102031.

The spelling of 22664781 in words is "twenty-two million, six hundred sixty-four thousand, seven hundred eighty-one".