22731281 has 2 divisors, whose sum is σ = 22731282. Its totient is φ = 22731280.

The previous prime is 22731263. The next prime is 22731287. The reversal of 22731281 is 18213722.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21242881 + 1488400 = 4609^2 + 1220^2 .

It is a cyclic number.

It is not a de Polignac number, because 22731281 - 2⁶ = 22731217 is a prime.

It is a super-2 number, since 2×22731281² = 1033422271801922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 22731281.

It is not a weakly prime, because it can be changed into another prime (22731287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11365640 + 11365641.

It is an arithmetic number, because the mean of its divisors is an integer number (11365641).

Almost surely, 2^22731281 is an apocalyptic number.

It is an amenable number.

22731281 is a deficient number, since it is larger than the sum of its proper divisors (1).

22731281 is an equidigital number, since it uses as much as digits as its factorization.

22731281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 26.

The square root of 22731281 is about 4767.7333188844. The cubic root of 22731281 is about 283.2748186736.

The spelling of 22731281 in words is "twenty-two million, seven hundred thirty-one thousand, two hundred eighty-one".