22691381 has 4 divisors (see below), whose sum is σ = 22790700. Its totient is φ = 22592064.

The previous prime is 22691353. The next prime is 22691399. The reversal of 22691381 is 18319622.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20160100 + 2531281 = 4490^2 + 1591^2 .

It is a cyclic number.

It is not a de Polignac number, because 22691381 - 2¹⁴ = 22674997 is a prime.

It is a super-2 number, since 2×22691381² = 1029797543374322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22691321) 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, 49316 + ... + 49773.

It is an arithmetic number, because the mean of its divisors is an integer number (5697675).

Almost surely, 2^22691381 is an apocalyptic number.

It is an amenable number.

22691381 is a deficient number, since it is larger than the sum of its proper divisors (99319).

22691381 is an equidigital number, since it uses as much as digits as its factorization.

22691381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99318.

The product of its digits is 5184, while the sum is 32.

The square root of 22691381 is about 4763.5471027376. The cubic root of 22691381 is about 283.1089784104.

The spelling of 22691381 in words is "twenty-two million, six hundred ninety-one thousand, three hundred eighty-one".