21666732371 has 8 divisors (see below), whose sum is σ = 22172593344. Its totient is φ = 21160961640.

The previous prime is 21666732341. The next prime is 21666732377. The reversal of 21666732371 is 17323766612.

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

It is a cyclic number.

It is not a de Polignac number, because 21666732371 - 2³⁰ = 20592990547 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21666732377) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 869516 + ... + 894086.

It is an arithmetic number, because the mean of its divisors is an integer number (2771574168).

Almost surely, 2^21666732371 is an apocalyptic number.

21666732371 is a deficient number, since it is larger than the sum of its proper divisors (505860973).

21666732371 is a wasteful number, since it uses less digits than its factorization.

21666732371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45121.

The product of its digits is 381024, while the sum is 44.

The spelling of 21666732371 in words is "twenty-one billion, six hundred sixty-six million, seven hundred thirty-two thousand, three hundred seventy-one".