20028493 has 4 divisors (see below), whose sum is σ = 20086560. Its totient is φ = 19970428.

The previous prime is 20028467. The next prime is 20028509. The reversal of 20028493 is 39482002.

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-20028493 is a prime.

It is a super-2 number, since 2×20028493² = 802281063702098, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20028893) 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, 28513 + ... + 29206.

It is an arithmetic number, because the mean of its divisors is an integer number (5021640).

Almost surely, 2^20028493 is an apocalyptic number.

It is an amenable number.

20028493 is a deficient number, since it is larger than the sum of its proper divisors (58067).

20028493 is an equidigital number, since it uses as much as digits as its factorization.

20028493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58066.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20028493 is about 4475.3204354549. The cubic root of 20028493 is about 271.5706036625.

The spelling of 20028493 in words is "twenty million, twenty-eight thousand, four hundred ninety-three".