22781281 has 8 divisors (see below), whose sum is σ = 23401224. Its totient is φ = 22164480.

The previous prime is 22781279. The next prime is 22781287. The reversal of 22781281 is 18218722.

It can be written as a sum of positive squares in 4 ways, for example, as 266256 + 22515025 = 516^2 + 4745^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 22781281 - 2¹ = 22781279 is a prime.

It is a super-2 number, since 2×22781281² = 1037973528001922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22781287) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23845 + ... + 24781.

It is an arithmetic number, because the mean of its divisors is an integer number (2925153).

Almost surely, 2^22781281 is an apocalyptic number.

It is an amenable number.

22781281 is a deficient number, since it is larger than the sum of its proper divisors (619943).

22781281 is an equidigital number, since it uses as much as digits as its factorization.

22781281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1571.

The product of its digits is 3584, while the sum is 31.

The square root of 22781281 is about 4772.9740204615. The cubic root of 22781281 is about 283.4823648108.

The spelling of 22781281 in words is "twenty-two million, seven hundred eighty-one thousand, two hundred eighty-one".