21928745 has 8 divisors (see below), whose sum is σ = 26516160. Its totient is φ = 17408560.

The previous prime is 21928733. The next prime is 21928757. The reversal of 21928745 is 54782912.

It is an interprime number because it is at equal distance from previous prime (21928733) and next prime (21928757).

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

It is not a de Polignac number, because 21928745 - 2¹² = 21924649 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21928699 and 21928708.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16085 + ... + 17394.

It is an arithmetic number, because the mean of its divisors is an integer number (3314520).

Almost surely, 2^21928745 is an apocalyptic number.

It is an amenable number.

21928745 is a deficient number, since it is larger than the sum of its proper divisors (4587415).

21928745 is a wasteful number, since it uses less digits than its factorization.

21928745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33615.

The product of its digits is 40320, while the sum is 38.

The square root of 21928745 is about 4682.8137908740. The cubic root of 21928745 is about 279.9010917661.

The spelling of 21928745 in words is "twenty-one million, nine hundred twenty-eight thousand, seven hundred forty-five".