21049759 has 2 divisors, whose sum is σ = 21049760. Its totient is φ = 21049758.

The previous prime is 21049729. The next prime is 21049783. The reversal of 21049759 is 95794012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21049759 - 2⁵ = 21049727 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21049709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10524879 + 10524880.

It is an arithmetic number, because the mean of its divisors is an integer number (10524880).

Almost surely, 2^21049759 is an apocalyptic number.

21049759 is a deficient number, since it is larger than the sum of its proper divisors (1).

21049759 is an equidigital number, since it uses as much as digits as its factorization.

21049759 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 21049759 is about 4588.0016346989. The cubic root of 21049759 is about 276.1101525942.

The spelling of 21049759 in words is "twenty-one million, forty-nine thousand, seven hundred fifty-nine".