20963993 has 8 divisors (see below), whose sum is σ = 21331200. Its totient is φ = 20599488.

The previous prime is 20963989. The next prime is 20964001. The reversal of 20963993 is 39936902.

It is a happy number.

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 20963993 - 2² = 20963989 is a prime.

It is a super-3 number, since 3×20963993³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20963993.

It is not an unprimeable number, because it can be changed into a prime (20963923) 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, 20273 + ... + 21281.

It is an arithmetic number, because the mean of its divisors is an integer number (2666400).

Almost surely, 2^20963993 is an apocalyptic number.

It is an amenable number.

20963993 is a deficient number, since it is larger than the sum of its proper divisors (367207).

20963993 is a wasteful number, since it uses less digits than its factorization.

20963993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1351.

The product of its (nonzero) digits is 78732, while the sum is 41.

The square root of 20963993 is about 4578.6453236738. The cubic root of 20963993 is about 275.7346439650.

The spelling of 20963993 in words is "twenty million, nine hundred sixty-three thousand, nine hundred ninety-three".