21992843 has 2 divisors, whose sum is σ = 21992844. Its totient is φ = 21992842.

The previous prime is 21992833. The next prime is 21992863. The reversal of 21992843 is 34829912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21992843 - 2⁸ = 21992587 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21992797 and 21992806.

It is not a weakly prime, because it can be changed into another prime (21992833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10996421 + 10996422.

It is an arithmetic number, because the mean of its divisors is an integer number (10996422).

Almost surely, 2^21992843 is an apocalyptic number.

21992843 is a deficient number, since it is larger than the sum of its proper divisors (1).

21992843 is an equidigital number, since it uses as much as digits as its factorization.

21992843 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 38.

The square root of 21992843 is about 4689.6527590004. The cubic root of 21992843 is about 280.1735446253.

The spelling of 21992843 in words is "twenty-one million, nine hundred ninety-two thousand, eight hundred forty-three".