21935939 has 2 divisors, whose sum is σ = 21935940. Its totient is φ = 21935938.

The previous prime is 21935917. The next prime is 21935983. The reversal of 21935939 is 93953912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21935939 - 2¹⁶ = 21870403 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21935896 and 21935905.

It is not a weakly prime, because it can be changed into another prime (21935909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10967969 + 10967970.

It is an arithmetic number, because the mean of its divisors is an integer number (10967970).

Almost surely, 2^21935939 is an apocalyptic number.

21935939 is a deficient number, since it is larger than the sum of its proper divisors (1).

21935939 is an equidigital number, since it uses as much as digits as its factorization.

21935939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 65610, while the sum is 41.

The square root of 21935939 is about 4683.5818558022. The cubic root of 21935939 is about 279.9316967748.

The spelling of 21935939 in words is "twenty-one million, nine hundred thirty-five thousand, nine hundred thirty-nine".