21736906386 has 16 divisors (see below), whose sum is σ = 46817952384. Its totient is φ = 6688278864.

The previous prime is 21736906351. The next prime is 21736906391. The reversal of 21736906386 is 68360963712.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 139339066 + ... + 139339221.

It is an arithmetic number, because the mean of its divisors is an integer number (2926122024).

Almost surely, 2^21736906386 is an apocalyptic number.

21736906386 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21736906386 is an abundant number, since it is smaller than the sum of its proper divisors (25081045998).

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

21736906386 is a wasteful number, since it uses less digits than its factorization.

21736906386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278678305.

The product of its (nonzero) digits is 1959552, while the sum is 51.

The spelling of 21736906386 in words is "twenty-one billion, seven hundred thirty-six million, nine hundred six thousand, three hundred eighty-six".