20279947 has 4 divisors (see below), whose sum is σ = 20291040. Its totient is φ = 20268856.

The previous prime is 20279939. The next prime is 20279957. The reversal of 20279947 is 74997202.

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 is a cyclic number.

It is not a de Polignac number, because 20279947 - 2³ = 20279939 is a prime.

It is a super-3 number, since 3×20279947³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20279927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2083 + ... + 6700.

It is an arithmetic number, because the mean of its divisors is an integer number (5072760).

Almost surely, 2^20279947 is an apocalyptic number.

20279947 is a deficient number, since it is larger than the sum of its proper divisors (11093).

20279947 is an equidigital number, since it uses as much as digits as its factorization.

20279947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11092.

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 20279947 is about 4503.3262151436. The cubic root of 20279947 is about 272.7023864733.

The spelling of 20279947 in words is "twenty million, two hundred seventy-nine thousand, nine hundred forty-seven".