21949403 has 12 divisors (see below), whose sum is σ = 25786800. Its totient is φ = 18626832.

The previous prime is 21949387. The next prime is 21949409. The reversal of 21949403 is 30494912.

It is a happy number.

It is not a de Polignac number, because 21949403 - 2⁴ = 21949387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21949403.

It is not an unprimeable number, because it can be changed into a prime (21949409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2873 + ... + 7221.

It is an arithmetic number, because the mean of its divisors is an integer number (2148900).

Almost surely, 2^21949403 is an apocalyptic number.

21949403 is a deficient number, since it is larger than the sum of its proper divisors (3837397).

21949403 is a wasteful number, since it uses less digits than its factorization.

21949403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4466 (or 4459 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21949403 is about 4685.0189967598. The cubic root of 21949403 is about 279.9889578979.

The spelling of 21949403 in words is "twenty-one million, nine hundred forty-nine thousand, four hundred three".