20745947 has 8 divisors (see below), whose sum is σ = 21134400. Its totient is φ = 20359944.

The previous prime is 20745911. The next prime is 20745971. The reversal of 20745947 is 74954702.

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

It is a cyclic number.

It is not a de Polignac number, because 20745947 - 2⁶ = 20745883 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20745947.

It is not an unprimeable number, because it can be changed into a prime (20745047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27704 + ... + 28442.

It is an arithmetic number, because the mean of its divisors is an integer number (2641800).

Almost surely, 2^20745947 is an apocalyptic number.

20745947 is a deficient number, since it is larger than the sum of its proper divisors (388453).

20745947 is an equidigital number, since it uses as much as digits as its factorization.

20745947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1225.

The product of its (nonzero) digits is 70560, while the sum is 38.

The square root of 20745947 is about 4554.7718933005. The cubic root of 20745947 is about 274.7753404827.

The spelling of 20745947 in words is "twenty million, seven hundred forty-five thousand, nine hundred forty-seven".