21903448 has 16 divisors (see below), whose sum is σ = 46936080. Its totient is φ = 9387168.

The previous prime is 21903443. The next prime is 21903449. The reversal of 21903448 is 84430912.

It is a super-2 number, since 2×21903448² = 959522068577408, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21903443) 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 3 ways as a sum of consecutive naturals, for example, 195511 + ... + 195622.

It is an arithmetic number, because the mean of its divisors is an integer number (2933505).

Almost surely, 2^21903448 is an apocalyptic number.

21903448 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21903448 is an abundant number, since it is smaller than the sum of its proper divisors (25032632).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21903448 is a wasteful number, since it uses less digits than its factorization.

21903448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391146 (or 391142 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 21903448 is about 4680.1119644726. Note that the first 3 decimals coincide. The cubic root of 21903448 is about 279.7934190529.

The spelling of 21903448 in words is "twenty-one million, nine hundred three thousand, four hundred forty-eight".