20867993 has 8 divisors (see below), whose sum is σ = 22146120. Its totient is φ = 19595520.

The previous prime is 20867989. The next prime is 20868007. The reversal of 20867993 is 39976802.

It can be written as a sum of positive squares in 4 ways, for example, as 824464 + 20043529 = 908^2 + 4477^2 .

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 20867993 - 2² = 20867989 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20867933) 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, 8063 + ... + 10331.

It is an arithmetic number, because the mean of its divisors is an integer number (2768265).

Almost surely, 2^20867993 is an apocalyptic number.

It is an amenable number.

20867993 is a deficient number, since it is larger than the sum of its proper divisors (1278127).

20867993 is a wasteful number, since it uses less digits than its factorization.

20867993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2827.

The product of its (nonzero) digits is 163296, while the sum is 44.

The square root of 20867993 is about 4568.1498443024. The cubic root of 20867993 is about 275.3131111294.

It can be divided in two parts, 2086799 and 3, that added together give a palindrome (2086802).

The spelling of 20867993 in words is "twenty million, eight hundred sixty-seven thousand, nine hundred ninety-three".