20912947 has 4 divisors (see below), whose sum is σ = 22814136. Its totient is φ = 19011760.

The previous prime is 20912923. The next prime is 20912989. The reversal of 20912947 is 74921902.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20912947 - 2¹⁵ = 20880179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20912917) 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, 950578 + ... + 950599.

It is an arithmetic number, because the mean of its divisors is an integer number (5703534).

Almost surely, 2^20912947 is an apocalyptic number.

20912947 is a deficient number, since it is larger than the sum of its proper divisors (1901189).

20912947 is a wasteful number, since it uses less digits than its factorization.

20912947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1901188.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 20912947 is about 4573.0675700234. The cubic root of 20912947 is about 275.5106632544.

The spelling of 20912947 in words is "twenty million, nine hundred twelve thousand, nine hundred forty-seven".