21673278836 has 12 divisors (see below), whose sum is σ = 41376259680. Its totient is φ = 9851490360.

The previous prime is 21673278821. The next prime is 21673278839. The reversal of 21673278836 is 63887237612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21673278839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 246287216 + ... + 246287303.

It is an arithmetic number, because the mean of its divisors is an integer number (3448021640).

Almost surely, 2^21673278836 is an apocalyptic number.

It is an amenable number.

21673278836 is a deficient number, since it is larger than the sum of its proper divisors (19702980844).

21673278836 is a wasteful number, since it uses less digits than its factorization.

21673278836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492574534 (or 492574532 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 53.

The spelling of 21673278836 in words is "twenty-one billion, six hundred seventy-three million, two hundred seventy-eight thousand, eight hundred thirty-six".