20743993 has 4 divisors (see below), whose sum is σ = 20779920. Its totient is φ = 20708068.

The previous prime is 20743979. The next prime is 20744021. The reversal of 20743993 is 39934702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20743993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20743973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17083 + ... + 18256.

It is an arithmetic number, because the mean of its divisors is an integer number (5194980).

Almost surely, 2^20743993 is an apocalyptic number.

It is an amenable number.

20743993 is a deficient number, since it is larger than the sum of its proper divisors (35927).

20743993 is an equidigital number, since it uses as much as digits as its factorization.

20743993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35926.

The product of its (nonzero) digits is 40824, while the sum is 37.

The square root of 20743993 is about 4554.5573879357. The cubic root of 20743993 is about 274.7667134503.

It can be divided in two parts, 20743 and 993, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 20743993 in words is "twenty million, seven hundred forty-three thousand, nine hundred ninety-three".