21756054266 has 8 divisors (see below), whose sum is σ = 34553733300. Its totient is φ = 10238143168.

The previous prime is 21756054251. The next prime is 21756054277. The reversal of 21756054266 is 66245065712.

It can be written as a sum of positive squares in 2 ways, for example, as 18110430625 + 3645623641 = 134575^2 + 60379^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 319941941 + ... + 319942008.

Almost surely, 2^21756054266 is an apocalyptic number.

21756054266 is a deficient number, since it is larger than the sum of its proper divisors (12797679034).

21756054266 is a wasteful number, since it uses less digits than its factorization.

21756054266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639883968.

The product of its (nonzero) digits is 604800, while the sum is 44.

The spelling of 21756054266 in words is "twenty-one billion, seven hundred fifty-six million, fifty-four thousand, two hundred sixty-six".