21850039 has 2 divisors, whose sum is σ = 21850040. Its totient is φ = 21850038.

The previous prime is 21850027. The next prime is 21850043. The reversal of 21850039 is 93005812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21850039 - 2⁷ = 21849911 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21849989 and 21850016.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21850099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10925019 + 10925020.

It is an arithmetic number, because the mean of its divisors is an integer number (10925020).

Almost surely, 2^21850039 is an apocalyptic number.

21850039 is a deficient number, since it is larger than the sum of its proper divisors (1).

21850039 is an equidigital number, since it uses as much as digits as its factorization.

21850039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 21850039 is about 4674.4025286661. The cubic root of 21850039 is about 279.5658194351.

The spelling of 21850039 in words is "twenty-one million, eight hundred fifty thousand, thirty-nine".