21497717612 has 24 divisors (see below), whose sum is σ = 43016739360. Its totient is φ = 9208742400.

The previous prime is 21497717611. The next prime is 21497717617. The reversal of 21497717612 is 21671779412.

It is a happy number.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21497717611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132389 + ... + 246012.

It is an arithmetic number, because the mean of its divisors is an integer number (1792364140).

Almost surely, 2^21497717612 is an apocalyptic number.

It is an amenable number.

21497717612 is an abundant number, since it is smaller than the sum of its proper divisors (21519021748).

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

21497717612 is a wasteful number, since it uses less digits than its factorization.

21497717612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380441 (or 380439 counting only the distinct ones).

The product of its digits is 296352, while the sum is 47.

The spelling of 21497717612 in words is "twenty-one billion, four hundred ninety-seven million, seven hundred seventeen thousand, six hundred twelve".