21941605 has 16 divisors (see below), whose sum is σ = 30167424. Its totient is φ = 15007680.

The previous prime is 21941581. The next prime is 21941651. The reversal of 21941605 is 50614912.

It is not a de Polignac number, because 21941605 - 2⁵ = 21941573 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26650 + ... + 27460.

It is an arithmetic number, because the mean of its divisors is an integer number (1885464).

Almost surely, 2^21941605 is an apocalyptic number.

It is an amenable number.

21941605 is a deficient number, since it is larger than the sum of its proper divisors (8225819).

21941605 is an equidigital number, since it uses as much as digits as its factorization.

21941605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1596.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 21941605 is about 4684.1866956815. The cubic root of 21941605 is about 279.9557965934.

The spelling of 21941605 in words is "twenty-one million, nine hundred forty-one thousand, six hundred five".