21363065691 has 32 divisors (see below), whose sum is σ = 33013951488. Its totient is φ = 12144023040.

The previous prime is 21363065671. The next prime is 21363065693. The reversal of 21363065691 is 19656036312.

It is not a de Polignac number, because 21363065691 - 2²⁷ = 21228847963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21363065693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 99390 + ... + 229356.

It is an arithmetic number, because the mean of its divisors is an integer number (1031685984).

Almost surely, 2^21363065691 is an apocalyptic number.

21363065691 is a deficient number, since it is larger than the sum of its proper divisors (11650885797).

21363065691 is a wasteful number, since it uses less digits than its factorization.

21363065691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130291.

The product of its (nonzero) digits is 174960, while the sum is 42.

The spelling of 21363065691 in words is "twenty-one billion, three hundred sixty-three million, sixty-five thousand, six hundred ninety-one".