22101581 has 8 divisors (see below), whose sum is σ = 23786424. Its totient is φ = 20459520.

The previous prime is 22101571. The next prime is 22101623. The reversal of 22101581 is 18510122.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 292681 + 21808900 = 541^2 + 4670^2 .

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 22101581 - 2⁶ = 22101517 is a prime.

It is a super-2 number, since 2×22101581² = 976959765399122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22101511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9620 + ... + 11693.

It is an arithmetic number, because the mean of its divisors is an integer number (2973303).

Almost surely, 2^22101581 is an apocalyptic number.

It is an amenable number.

22101581 is a deficient number, since it is larger than the sum of its proper divisors (1684843).

22101581 is a wasteful number, since it uses less digits than its factorization.

22101581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21391.

The product of its (nonzero) digits is 160, while the sum is 20.

The square root of 22101581 is about 4701.2318598427. The cubic root of 22101581 is about 280.6345345742.

The spelling of 22101581 in words is "twenty-two million, one hundred one thousand, five hundred eighty-one".