20791730 has 8 divisors (see below), whose sum is σ = 37425132. Its totient is φ = 8316688.

The previous prime is 20791723. The next prime is 20791739. The reversal of 20791730 is 3719702.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20638849 + 152881 = 4543^2 + 391^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 20791693 and 20791702.

It is not an unprimeable number, because it can be changed into a prime (20791739) 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, 1039577 + ... + 1039596.

Almost surely, 2^20791730 is an apocalyptic number.

20791730 is a deficient number, since it is larger than the sum of its proper divisors (16633402).

20791730 is a wasteful number, since it uses less digits than its factorization.

20791730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2079180.

The product of its (nonzero) digits is 2646, while the sum is 29.

The square root of 20791730 is about 4559.7949515302. The cubic root of 20791730 is about 274.9773204437.

The spelling of 20791730 in words is "twenty million, seven hundred ninety-one thousand, seven hundred thirty".