20219993 has 4 divisors (see below), whose sum is σ = 20229300. Its totient is φ = 20210688.

The previous prime is 20219951. The next prime is 20220007. The reversal of 20219993 is 39991202.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2647129 + 17572864 = 1627^2 + 4192^2 .

It is a cyclic number.

It is not a de Polignac number, because 20219993 - 2¹⁰ = 20218969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20219893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 533 + ... + 6381.

It is an arithmetic number, because the mean of its divisors is an integer number (5057325).

Almost surely, 2^20219993 is an apocalyptic number.

It is an amenable number.

20219993 is a deficient number, since it is larger than the sum of its proper divisors (9307).

20219993 is an equidigital number, since it uses as much as digits as its factorization.

20219993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9306.

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 20219993 is about 4496.6646528288. The cubic root of 20219993 is about 272.4333894367.

It can be divided in two parts, 20219 and 993, that added together give a palindrome (21212).

The spelling of 20219993 in words is "twenty million, two hundred nineteen thousand, nine hundred ninety-three".