21660566342 has 8 divisors (see below), whose sum is σ = 33903495216. Its totient is φ = 10359401272.

The previous prime is 21660566339. The next prime is 21660566359. The reversal of 21660566342 is 24366506612.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21660566342.

It is a congruent number.

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, 235440893 + ... + 235440984.

It is an arithmetic number, because the mean of its divisors is an integer number (4237936902).

Almost surely, 2^21660566342 is an apocalyptic number.

21660566342 is a deficient number, since it is larger than the sum of its proper divisors (12242928874).

21660566342 is a wasteful number, since it uses less digits than its factorization.

21660566342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470881902.

The product of its (nonzero) digits is 311040, while the sum is 41.

The spelling of 21660566342 in words is "twenty-one billion, six hundred sixty million, five hundred sixty-six thousand, three hundred forty-two".