21094745 has 24 divisors (see below), whose sum is σ = 30472200. Its totient is φ = 13961472.

The previous prime is 21094721. The next prime is 21094747. The reversal of 21094745 is 54749012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 8281 + 21086464 = 91^2 + 4592^2 .

It is not a de Polignac number, because 21094745 - 2¹⁴ = 21078361 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21094747) 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 23 ways as a sum of consecutive naturals, for example, 5621 + ... + 8589.

It is an arithmetic number, because the mean of its divisors is an integer number (1269675).

Almost surely, 2^21094745 is an apocalyptic number.

It is an amenable number.

21094745 is a deficient number, since it is larger than the sum of its proper divisors (9377455).

21094745 is a wasteful number, since it uses less digits than its factorization.

21094745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3017 (or 3010 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 21094745 is about 4592.9015883208. The cubic root of 21094745 is about 276.3067067580.

The spelling of 21094745 in words is "twenty-one million, ninety-four thousand, seven hundred forty-five".