21149659 has 2 divisors, whose sum is σ = 21149660. Its totient is φ = 21149658.

The previous prime is 21149629. The next prime is 21149663. The reversal of 21149659 is 95694112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21149659 is a prime.

It is not a weakly prime, because it can be changed into another prime (21149629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10574829 + 10574830.

It is an arithmetic number, because the mean of its divisors is an integer number (10574830).

Almost surely, 2^21149659 is an apocalyptic number.

21149659 is a deficient number, since it is larger than the sum of its proper divisors (1).

21149659 is an equidigital number, since it uses as much as digits as its factorization.

21149659 is an odious number, because the sum of its binary digits is odd.

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

The square root of 21149659 is about 4598.8758408985. The cubic root of 21149659 is about 276.5462602464.

The spelling of 21149659 in words is "twenty-one million, one hundred forty-nine thousand, six hundred fifty-nine".