20427749 has 4 divisors (see below), whose sum is σ = 21315936. Its totient is φ = 19539564.

The previous prime is 20427707. The next prime is 20427763. The reversal of 20427749 is 94772402.

It is a happy number.

20427749 is nontrivially palindromic in base 13.

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 not a de Polignac number, because 20427749 - 2¹² = 20423653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20421749) 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, 444059 + ... + 444104.

It is an arithmetic number, because the mean of its divisors is an integer number (5328984).

Almost surely, 2^20427749 is an apocalyptic number.

It is an amenable number.

20427749 is a deficient number, since it is larger than the sum of its proper divisors (888187).

20427749 is an equidigital number, since it uses as much as digits as its factorization.

20427749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 888186.

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 20427749 is about 4519.7067382741. The cubic root of 20427749 is about 273.3632763482.

The spelling of 20427749 in words is "twenty million, four hundred twenty-seven thousand, seven hundred forty-nine".