20990693 has 8 divisors (see below), whose sum is σ = 21772800. Its totient is φ = 20212528.

The previous prime is 20990677. The next prime is 20990707. The reversal of 20990693 is 39609902.

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

It is a cyclic number.

It is not a de Polignac number, because 20990693 - 2⁴ = 20990677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20990603) 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, 13868 + ... + 15306.

It is an arithmetic number, because the mean of its divisors is an integer number (2721600).

Almost surely, 2^20990693 is an apocalyptic number.

It is an amenable number.

20990693 is a deficient number, since it is larger than the sum of its proper divisors (782107).

20990693 is a wasteful number, since it uses less digits than its factorization.

20990693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1971.

The product of its (nonzero) digits is 26244, while the sum is 38.

The square root of 20990693 is about 4581.5601054663. The cubic root of 20990693 is about 275.8516539848.

The spelling of 20990693 in words is "twenty million, nine hundred ninety thousand, six hundred ninety-three".