20748999 has 4 divisors (see below), whose sum is σ = 27665336. Its totient is φ = 13832664.

The previous prime is 20748997. The next prime is 20749021. The reversal of 20748999 is 99984702.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20748999 - 2¹ = 20748997 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 (20748991) 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, 3458164 + ... + 3458169.

It is an arithmetic number, because the mean of its divisors is an integer number (6916334).

Almost surely, 2^20748999 is an apocalyptic number.

20748999 is a deficient number, since it is larger than the sum of its proper divisors (6916337).

20748999 is an equidigital number, since it uses as much as digits as its factorization.

20748999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6916336.

The product of its (nonzero) digits is 326592, while the sum is 48.

The square root of 20748999 is about 4555.1069142228. The cubic root of 20748999 is about 274.7888141702.

The spelling of 20748999 in words is "twenty million, seven hundred forty-eight thousand, nine hundred ninety-nine".