20847663 has 6 divisors (see below), whose sum is σ = 30113304. Its totient is φ = 13898436.

The previous prime is 20847643. The next prime is 20847679. The reversal of 20847663 is 36674802.

It is not a de Polignac number, because 20847663 - 2⁶ = 20847599 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20847623) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1158195 + ... + 1158212.

It is an arithmetic number, because the mean of its divisors is an integer number (5018884).

Almost surely, 2^20847663 is an apocalyptic number.

20847663 is a deficient number, since it is larger than the sum of its proper divisors (9265641).

20847663 is a wasteful number, since it uses less digits than its factorization.

20847663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2316413 (or 2316410 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 20847663 is about 4565.9241123786. The cubic root of 20847663 is about 275.2236769715.

The spelling of 20847663 in words is "twenty million, eight hundred forty-seven thousand, six hundred sixty-three".