21793787830 has 16 divisors (see below), whose sum is σ = 39306816864. Its totient is φ = 8700182080.

The previous prime is 21793787809. The next prime is 21793787849. The reversal of 21793787830 is 3878739712.

It is a happy number.

It is a super-2 number, since 2×21793787830² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 2161351 + ... + 2171410.

It is an arithmetic number, because the mean of its divisors is an integer number (2456676054).

Almost surely, 2^21793787830 is an apocalyptic number.

21793787830 is a deficient number, since it is larger than the sum of its proper divisors (17513029034).

21793787830 is a wasteful number, since it uses less digits than its factorization.

21793787830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4333271.

The product of its (nonzero) digits is 3556224, while the sum is 55.

The spelling of 21793787830 in words is "twenty-one billion, seven hundred ninety-three million, seven hundred eighty-seven thousand, eight hundred thirty".