22157281 has 4 divisors (see below), whose sum is σ = 22872064. Its totient is φ = 21442500.

The previous prime is 22157269. The next prime is 22157293. The reversal of 22157281 is 18275122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (22157269) and next prime (22157293).

It is a cyclic number.

It is not a de Polignac number, because 22157281 - 2¹⁵ = 22124513 is a prime.

It is a super-2 number, since 2×22157281² = 981890202625922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22157081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 357345 + ... + 357406.

It is an arithmetic number, because the mean of its divisors is an integer number (5718016).

Almost surely, 2^22157281 is an apocalyptic number.

It is an amenable number.

22157281 is a deficient number, since it is larger than the sum of its proper divisors (714783).

22157281 is an equidigital number, since it uses as much as digits as its factorization.

22157281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714782.

The product of its digits is 2240, while the sum is 28.

The square root of 22157281 is about 4707.1521114151. The cubic root of 22157281 is about 280.8700868130.

The spelling of 22157281 in words is "twenty-two million, one hundred fifty-seven thousand, two hundred eighty-one".