22219781 has 2 divisors, whose sum is σ = 22219782. Its totient is φ = 22219780.

The previous prime is 22219763. The next prime is 22219823. The reversal of 22219781 is 18791222.

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., 21808900 + 410881 = 4670^2 + 641^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22219781 is a prime.

It is a super-2 number, since 2×22219781² = 987437335375922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22219751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11109890 + 11109891.

It is an arithmetic number, because the mean of its divisors is an integer number (11109891).

Almost surely, 2^22219781 is an apocalyptic number.

It is an amenable number.

22219781 is a deficient number, since it is larger than the sum of its proper divisors (1).

22219781 is an equidigital number, since it uses as much as digits as its factorization.

22219781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 32.

The square root of 22219781 is about 4713.7862700806. The cubic root of 22219781 is about 281.1339263574.

The spelling of 22219781 in words is "twenty-two million, two hundred nineteen thousand, seven hundred eighty-one".