21666232715 has 8 divisors (see below), whose sum is σ = 26010637488. Its totient is φ = 17325547360.

The previous prime is 21666232681. The next prime is 21666232771. The reversal of 21666232715 is 51723266612.

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

It is not a de Polignac number, because 21666232715 - 2²⁶ = 21599123851 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 917021 + ... + 940350.

It is an arithmetic number, because the mean of its divisors is an integer number (3251329686).

Almost surely, 2^21666232715 is an apocalyptic number.

21666232715 is a deficient number, since it is larger than the sum of its proper divisors (4344404773).

21666232715 is a wasteful number, since it uses less digits than its factorization.

21666232715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1859709.

The product of its digits is 181440, while the sum is 41.

The spelling of 21666232715 in words is "twenty-one billion, six hundred sixty-six million, two hundred thirty-two thousand, seven hundred fifteen".