21881903 has 2 divisors, whose sum is σ = 21881904. Its totient is φ = 21881902.

The previous prime is 21881891. The next prime is 21881917. The reversal of 21881903 is 30918812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21881903 - 2⁸ = 21881647 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21881903.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21881963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10940951 + 10940952.

It is an arithmetic number, because the mean of its divisors is an integer number (10940952).

Almost surely, 2^21881903 is an apocalyptic number.

21881903 is a deficient number, since it is larger than the sum of its proper divisors (1).

21881903 is an equidigital number, since it uses as much as digits as its factorization.

21881903 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 21881903 is about 4677.8096369989. The cubic root of 21881903 is about 279.7016507493.

The spelling of 21881903 in words is "twenty-one million, eight hundred eighty-one thousand, nine hundred three".