20994643 has 8 divisors (see below), whose sum is σ = 22317120. Its totient is φ = 19681920.

The previous prime is 20994569. The next prime is 20994647. The reversal of 20994643 is 34649902.

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

It is not a de Polignac number, because 20994643 - 2⁹ = 20994131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20994647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2278 + ... + 6868.

It is an arithmetic number, because the mean of its divisors is an integer number (2789640).

Almost surely, 2^20994643 is an apocalyptic number.

20994643 is a deficient number, since it is larger than the sum of its proper divisors (1322477).

20994643 is a wasteful number, since it uses less digits than its factorization.

20994643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4877.

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 20994643 is about 4581.9911610565. The cubic root of 20994643 is about 275.8689560290.

The spelling of 20994643 in words is "twenty million, nine hundred ninety-four thousand, six hundred forty-three".