21661105514 has 8 divisors (see below), whose sum is σ = 32565672480. Its totient is φ = 10805881356.

The previous prime is 21661105513. The next prime is 21661105519. The reversal of 21661105514 is 41550116612.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21661105513) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 12334604 + ... + 12336359.

It is an arithmetic number, because the mean of its divisors is an integer number (4070709060).

Almost surely, 2^21661105514 is an apocalyptic number.

21661105514 is a deficient number, since it is larger than the sum of its proper divisors (10904566966).

21661105514 is a wasteful number, since it uses less digits than its factorization.

21661105514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24671404.

The product of its (nonzero) digits is 7200, while the sum is 32.

The spelling of 21661105514 in words is "twenty-one billion, six hundred sixty-one million, one hundred five thousand, five hundred fourteen".