21655719834 has 24 divisors (see below), whose sum is σ = 50382695808. Its totient is φ = 6187348440.

The previous prime is 21655719733. The next prime is 21655719847. The reversal of 21655719834 is 43891755612.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36829162 + ... + 36829749.

It is an arithmetic number, because the mean of its divisors is an integer number (2099278992).

Almost surely, 2^21655719834 is an apocalyptic number.

21655719834 is an abundant number, since it is smaller than the sum of its proper divisors (28726975974).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21655719834 is a wasteful number, since it uses less digits than its factorization.

21655719834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73658930 (or 73658923 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 51.

The spelling of 21655719834 in words is "twenty-one billion, six hundred fifty-five million, seven hundred nineteen thousand, eight hundred thirty-four".