20761663 has 12 divisors (see below), whose sum is σ = 23380840. Its totient is φ = 18325296.

The previous prime is 20761619. The next prime is 20761667. The reversal of 20761663 is 36616702.

It is a de Polignac number, because none of the positive numbers 2^k-20761663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20761667) 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, 5368 + ... + 8386.

Almost surely, 2^20761663 is an apocalyptic number.

20761663 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20761663 is a deficient number, since it is larger than the sum of its proper divisors (2619177).

20761663 is a wasteful number, since it uses less digits than its factorization.

20761663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3078 (or 3055 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 20761663 is about 4556.4967902984. The cubic root of 20761663 is about 274.8447079156.

The spelling of 20761663 in words is "twenty million, seven hundred sixty-one thousand, six hundred sixty-three".