22081781 has 8 divisors (see below), whose sum is σ = 23572800. Its totient is φ = 20623680.

The previous prime is 22081777. The next prime is 22081811. The reversal of 22081781 is 18718022.

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 22081781 - 2² = 22081777 is a prime.

It is a super-2 number, since 2×22081781² = 975210104263922, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22081721) 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, 6836 + ... + 9533.

It is an arithmetic number, because the mean of its divisors is an integer number (2946600).

Almost surely, 2^22081781 is an apocalyptic number.

It is an amenable number.

22081781 is a deficient number, since it is larger than the sum of its proper divisors (1491019).

22081781 is a wasteful number, since it uses less digits than its factorization.

22081781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16459.

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 22081781 is about 4699.1255569521. The cubic root of 22081781 is about 280.5507061229.

The spelling of 22081781 in words is "twenty-two million, eighty-one thousand, seven hundred eighty-one".