22356781 has 2 divisors, whose sum is σ = 22356782. Its totient is φ = 22356780.

The previous prime is 22356773. The next prime is 22356793. The reversal of 22356781 is 18765322.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21771556 + 585225 = 4666^2 + 765^2 .

It is a cyclic number.

It is not a de Polignac number, because 22356781 - 2³ = 22356773 is a prime.

It is a super-2 number, since 2×22356781² = 999651313363922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22386781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11178390 + 11178391.

It is an arithmetic number, because the mean of its divisors is an integer number (11178391).

Almost surely, 2^22356781 is an apocalyptic number.

It is an amenable number.

22356781 is a deficient number, since it is larger than the sum of its proper divisors (1).

22356781 is an equidigital number, since it uses as much as digits as its factorization.

22356781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20160, while the sum is 34.

The square root of 22356781 is about 4728.2957817802. The cubic root of 22356781 is about 281.7105366041.

The spelling of 22356781 in words is "twenty-two million, three hundred fifty-six thousand, seven hundred eighty-one".