20947843 has 12 divisors (see below), whose sum is σ = 24964632. Its totient is φ = 17515680.

The previous prime is 20947811. The next prime is 20947867. The reversal of 20947843 is 34874902.

It is a happy number.

It is not a de Polignac number, because 20947843 - 2⁵ = 20947811 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20947873) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3205 + ... + 7222.

It is an arithmetic number, because the mean of its divisors is an integer number (2080386).

Almost surely, 2^20947843 is an apocalyptic number.

20947843 is a deficient number, since it is larger than the sum of its proper divisors (4016789).

20947843 is a wasteful number, since it uses less digits than its factorization.

20947843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10482 (or 10475 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 20947843 is about 4576.8813618008. The cubic root of 20947843 is about 275.6638200130.

The spelling of 20947843 in words is "twenty million, nine hundred forty-seven thousand, eight hundred forty-three".