21094645 has 32 divisors (see below), whose sum is σ = 30086784. Its totient is φ = 13996800.

The previous prime is 21094631. The next prime is 21094649. The reversal of 21094645 is 54649012.

21094645 = T₁₄₄ + T₁₄₅ + ... + T₅₀₅.

It is not a de Polignac number, because 21094645 - 2⁷ = 21094517 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21094649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 116455 + ... + 116635.

It is an arithmetic number, because the mean of its divisors is an integer number (940212).

Almost surely, 2^21094645 is an apocalyptic number.

It is an amenable number.

21094645 is a deficient number, since it is larger than the sum of its proper divisors (8992139).

21094645 is a wasteful number, since it uses less digits than its factorization.

21094645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 21094645 is about 4592.8907019436. The cubic root of 21094645 is about 276.3062701451.

The spelling of 21094645 in words is "twenty-one million, ninety-four thousand, six hundred forty-five".