21506869276744 has 16 divisors (see below), whose sum is σ = 40455043499520. Its totient is φ = 10718857676880.

The previous prime is 21506869276741. The next prime is 21506869276757. The reversal of 21506869276744 is 44767296860512.

It is a self number, because there is not a number n which added to its sum of digits gives 21506869276744.

It is not an unprimeable number, because it can be changed into a prime (21506869276741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4322117544 + ... + 4322122519.

It is an arithmetic number, because the mean of its divisors is an integer number (2528440218720).

Almost surely, 2^{21506869276744} is an apocalyptic number.

It is an amenable number.

21506869276744 is a deficient number, since it is larger than the sum of its proper divisors (18948174222776).

21506869276744 is a wasteful number, since it uses less digits than its factorization.

21506869276744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8644240380 (or 8644240376 counting only the distinct ones).

The product of its (nonzero) digits is 243855360, while the sum is 67.

The spelling of 21506869276744 in words is "twenty-one trillion, five hundred six billion, eight hundred sixty-nine million, two hundred seventy-six thousand, seven hundred forty-four".