20781963 has 12 divisors (see below), whose sum is σ = 30101760. Its totient is φ = 13816176.

The previous prime is 20781931. The next prime is 20782031. The reversal of 20781963 is 36918702.

It is not a de Polignac number, because 20781963 - 2⁵ = 20781931 is a prime.

It is a super-2 number, since 2×20781963² = 863779972266738, which contains 22 as substring.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (20781263) 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, 433 + ... + 6461.

It is an arithmetic number, because the mean of its divisors is an integer number (2508480).

Almost surely, 2^20781963 is an apocalyptic number.

20781963 is a deficient number, since it is larger than the sum of its proper divisors (9319797).

20781963 is a wasteful number, since it uses less digits than its factorization.

20781963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6418 (or 6415 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 20781963 is about 4558.7238345835. The cubic root of 20781963 is about 274.9342564604.

The spelling of 20781963 in words is "twenty million, seven hundred eighty-one thousand, nine hundred sixty-three".