21074239 has 2 divisors, whose sum is σ = 21074240. Its totient is φ = 21074238.

The previous prime is 21074227. The next prime is 21074311. The reversal of 21074239 is 93247012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21074239 - 2⁷ = 21074111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21074639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10537119 + 10537120.

It is an arithmetic number, because the mean of its divisors is an integer number (10537120).

Almost surely, 2^21074239 is an apocalyptic number.

21074239 is a deficient number, since it is larger than the sum of its proper divisors (1).

21074239 is an equidigital number, since it uses as much as digits as its factorization.

21074239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 21074239 is about 4590.6686876750. The cubic root of 21074239 is about 276.2171460284.

The spelling of 21074239 in words is "twenty-one million, seventy-four thousand, two hundred thirty-nine".