22221681 has 8 divisors (see below), whose sum is σ = 30188160. Its totient is φ = 14534832.

The previous prime is 22221649. The next prime is 22221691. The reversal of 22221681 is 18612222.

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

It is not a de Polignac number, because 22221681 - 2⁵ = 22221649 is a prime.

It is a super-2 number, since 2×22221681² = 987606212931522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (22221691) 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, 69721 + ... + 70038.

It is an arithmetic number, because the mean of its divisors is an integer number (3773520).

Almost surely, 2^22221681 is an apocalyptic number.

It is an amenable number.

22221681 is a deficient number, since it is larger than the sum of its proper divisors (7966479).

22221681 is a wasteful number, since it uses less digits than its factorization.

22221681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139815.

The product of its digits is 768, while the sum is 24.

The square root of 22221681 is about 4713.9878022753. The cubic root of 22221681 is about 281.1419393262.

The spelling of 22221681 in words is "twenty-two million, two hundred twenty-one thousand, six hundred eighty-one".