21095949 has 16 divisors (see below), whose sum is σ = 32348672. Its totient is φ = 11978928.

The previous prime is 21095939. The next prime is 21095953. The reversal of 21095949 is 94959012.

It is not a de Polignac number, because 21095949 - 2⁸ = 21095693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21095939) 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 in 15 ways as a sum of consecutive naturals, for example, 342 + ... + 6504.

It is an arithmetic number, because the mean of its divisors is an integer number (2021792).

Almost surely, 2^21095949 is an apocalyptic number.

It is an amenable number.

21095949 is a deficient number, since it is larger than the sum of its proper divisors (11252723).

21095949 is a wasteful number, since it uses less digits than its factorization.

21095949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6336.

The product of its (nonzero) digits is 29160, while the sum is 39.

The square root of 21095949 is about 4593.0326582771. The cubic root of 21095949 is about 276.3119634692.

The spelling of 21095949 in words is "twenty-one million, ninety-five thousand, nine hundred forty-nine".