21950839 has 2 divisors, whose sum is σ = 21950840. Its totient is φ = 21950838.

The previous prime is 21950837. The next prime is 21950843. The reversal of 21950839 is 93805912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21950839 - 2¹ = 21950837 is a prime.

Together with 21950837, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21950798 and 21950807.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21950837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10975419 + 10975420.

It is an arithmetic number, because the mean of its divisors is an integer number (10975420).

Almost surely, 2^21950839 is an apocalyptic number.

21950839 is a deficient number, since it is larger than the sum of its proper divisors (1).

21950839 is an equidigital number, since it uses as much as digits as its factorization.

21950839 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 21950839 is about 4685.1722487012. The cubic root of 21950839 is about 279.9950636885.

The spelling of 21950839 in words is "twenty-one million, nine hundred fifty thousand, eight hundred thirty-nine".