21905896 has 32 divisors (see below), whose sum is σ = 41977440. Its totient is φ = 10715328.

The previous prime is 21905861. The next prime is 21905899. The reversal of 21905896 is 69850912.

It is not an unprimeable number, because it can be changed into a prime (21905899) 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 7 ways as a sum of consecutive naturals, for example, 134311 + ... + 134473.

It is an arithmetic number, because the mean of its divisors is an integer number (1311795).

Almost surely, 2^21905896 is an apocalyptic number.

It is an amenable number.

21905896 is a deficient number, since it is larger than the sum of its proper divisors (20071544).

21905896 is a wasteful number, since it uses less digits than its factorization.

21905896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 433 (or 429 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 21905896 is about 4680.3734893703. The cubic root of 21905896 is about 279.8038422029.

It can be divided in two parts, 21905 and 896, that added together give a square (22801 = 151²).

The spelling of 21905896 in words is "twenty-one million, nine hundred five thousand, eight hundred ninety-six".