21921105 has 8 divisors (see below), whose sum is σ = 35073792. Its totient is φ = 11691248.

The previous prime is 21921083. The next prime is 21921113. The reversal of 21921105 is 50112912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21921105 is a prime.

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, 730689 + ... + 730718.

It is an arithmetic number, because the mean of its divisors is an integer number (4384224).

Almost surely, 2^21921105 is an apocalyptic number.

It is an amenable number.

21921105 is a deficient number, since it is larger than the sum of its proper divisors (13152687).

21921105 is a wasteful number, since it uses less digits than its factorization.

21921105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1461415.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 21921105 is about 4681.9979709521. The cubic root of 21921105 is about 279.8685820361.

The spelling of 21921105 in words is "twenty-one million, nine hundred twenty-one thousand, one hundred five".