20907993 has 8 divisors (see below), whose sum is σ = 28090656. Its totient is φ = 13832000.

The previous prime is 20907983. The next prime is 20908001. The reversal of 20907993 is 39970902.

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 20907993 - 2¹⁰ = 20906969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20907983) 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, 26208 + ... + 26993.

It is an arithmetic number, because the mean of its divisors is an integer number (3511332).

Almost surely, 2^20907993 is an apocalyptic number.

It is an amenable number.

20907993 is a deficient number, since it is larger than the sum of its proper divisors (7182663).

20907993 is a wasteful number, since it uses less digits than its factorization.

20907993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53335.

The product of its (nonzero) digits is 30618, while the sum is 39.

The square root of 20907993 is about 4572.5258883904. The cubic root of 20907993 is about 275.4889065947.

The spelling of 20907993 in words is "twenty million, nine hundred seven thousand, nine hundred ninety-three".