21660561556234 has 8 divisors (see below), whose sum is σ = 32511576763008. Its totient is φ = 10823369301900.

The previous prime is 21660561556211. The next prime is 21660561556253. The reversal of 21660561556234 is 43265516506612.

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, 3455734192 + ... + 3455740459.

It is an arithmetic number, because the mean of its divisors is an integer number (4063947095376).

Almost surely, 2^{21660561556234} is an apocalyptic number.

21660561556234 is a deficient number, since it is larger than the sum of its proper divisors (10851015206774).

21660561556234 is a wasteful number, since it uses less digits than its factorization.

21660561556234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6911476220.

The product of its (nonzero) digits is 7776000, while the sum is 52.

The spelling of 21660561556234 in words is "twenty-one trillion, six hundred sixty billion, five hundred sixty-one million, five hundred fifty-six thousand, two hundred thirty-four".