21688767386 has 32 divisors (see below), whose sum is σ = 38268417600. Its totient is φ = 9088836480.

The previous prime is 21688767313. The next prime is 21688767391. The reversal of 21688767386 is 68376788612.

21688767386 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 184505 + ... + 278243.

It is an arithmetic number, because the mean of its divisors is an integer number (1195888050).

Almost surely, 2^21688767386 is an apocalyptic number.

21688767386 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21688767386 is a deficient number, since it is larger than the sum of its proper divisors (16579650214).

21688767386 is a wasteful number, since it uses less digits than its factorization.

21688767386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94574.

The product of its digits is 32514048, while the sum is 62.

The spelling of 21688767386 in words is "twenty-one billion, six hundred eighty-eight million, seven hundred sixty-seven thousand, three hundred eighty-six".