20649766918 has 12 divisors (see below), whose sum is σ = 33791630652. Its totient is φ = 9385951320.

The previous prime is 20649766871. The next prime is 20649766939. The reversal of 20649766918 is 81966794602.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 658696 + ... + 689332.

It is an arithmetic number, because the mean of its divisors is an integer number (2815969221).

Almost surely, 2^20649766918 is an apocalyptic number.

20649766918 is a deficient number, since it is larger than the sum of its proper divisors (13141863734).

20649766918 is an frugal number, since it uses more digits than its factorization.

20649766918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61287 (or 30650 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 58.

The spelling of 20649766918 in words is "twenty billion, six hundred forty-nine million, seven hundred sixty-six thousand, nine hundred eighteen".