21291265963 has 16 divisors (see below), whose sum is σ = 23723783424. Its totient is φ = 18945257760.

The previous prime is 21291265951. The next prime is 21291265969. The reversal of 21291265963 is 36956219212.

It is a de Polignac number, because none of the positive numbers 2^k-21291265963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21291265969) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23706 + ... + 207712.

It is an arithmetic number, because the mean of its divisors is an integer number (1482736464).

Almost surely, 2^21291265963 is an apocalyptic number.

21291265963 is a deficient number, since it is larger than the sum of its proper divisors (2432517461).

21291265963 is a wasteful number, since it uses less digits than its factorization.

21291265963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184242.

The product of its digits is 349920, while the sum is 46.

The spelling of 21291265963 in words is "twenty-one billion, two hundred ninety-one million, two hundred sixty-five thousand, nine hundred sixty-three".