21139337 has 2 divisors, whose sum is σ = 21139338. Its totient is φ = 21139336.

The previous prime is 21139301. The next prime is 21139379. The reversal of 21139337 is 73393112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20647936 + 491401 = 4544^2 + 701^2 .

It is a cyclic number.

It is not a de Polignac number, because 21139337 - 2²⁴ = 4362121 is a prime.

It is not a weakly prime, because it can be changed into another prime (21139397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10569668 + 10569669.

It is an arithmetic number, because the mean of its divisors is an integer number (10569669).

Almost surely, 2^21139337 is an apocalyptic number.

It is an amenable number.

21139337 is a deficient number, since it is larger than the sum of its proper divisors (1).

21139337 is an equidigital number, since it uses as much as digits as its factorization.

21139337 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3402, while the sum is 29.

The square root of 21139337 is about 4597.7534731649. The cubic root of 21139337 is about 276.5012638550.

The spelling of 21139337 in words is "twenty-one million, one hundred thirty-nine thousand, three hundred thirty-seven".