21905522 has 16 divisors (see below), whose sum is σ = 34473600. Its totient is φ = 10419552.

The previous prime is 21905519. The next prime is 21905531. The reversal of 21905522 is 22550912.

It is a junction number, because it is equal to n+sod(n) for n = 21905491 and 21905500.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7958 + ... + 10350.

It is an arithmetic number, because the mean of its divisors is an integer number (2154600).

Almost surely, 2^21905522 is an apocalyptic number.

21905522 is a deficient number, since it is larger than the sum of its proper divisors (12568078).

21905522 is a wasteful number, since it uses less digits than its factorization.

21905522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2617.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 21905522 is about 4680.3335351233. Note that the first 3 decimals coincide. The cubic root of 21905522 is about 279.8022498275.

The spelling of 21905522 in words is "twenty-one million, nine hundred five thousand, five hundred twenty-two".