21687355334 has 8 divisors (see below), whose sum is σ = 32532252480. Its totient is φ = 10843271176.

The previous prime is 21687355229. The next prime is 21687355337. The reversal of 21687355334 is 43355378612.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21687355337) 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, 131489 + ... + 246300.

It is an arithmetic number, because the mean of its divisors is an integer number (4066531560).

Almost surely, 2^21687355334 is an apocalyptic number.

21687355334 is a deficient number, since it is larger than the sum of its proper divisors (10844897146).

21687355334 is a wasteful number, since it uses less digits than its factorization.

21687355334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406494.

The product of its digits is 1814400, while the sum is 47.

The spelling of 21687355334 in words is "twenty-one billion, six hundred eighty-seven million, three hundred fifty-five thousand, three hundred thirty-four".