22220781 has 16 divisors (see below), whose sum is σ = 32406528. Its totient is φ = 13431600.

The previous prime is 22220777. The next prime is 22220791. The reversal of 22220781 is 18702222.

It is a happy number.

It is not a de Polignac number, because 22220781 - 2² = 22220777 is a prime.

It is a super-2 number, since 2×22220781² = 987526216499922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22220741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17436 + ... + 18666.

It is an arithmetic number, because the mean of its divisors is an integer number (2025408).

Almost surely, 2^22220781 is an apocalyptic number.

It is an amenable number.

22220781 is a deficient number, since it is larger than the sum of its proper divisors (10185747).

22220781 is a wasteful number, since it uses less digits than its factorization.

22220781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1792.

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 22220781 is about 4713.8923407307. The cubic root of 22220781 is about 281.1381437664.

The spelling of 22220781 in words is "twenty-two million, two hundred twenty thousand, seven hundred eighty-one".