21314475691 has 2 divisors, whose sum is σ = 21314475692. Its totient is φ = 21314475690.

The previous prime is 21314475673. The next prime is 21314475811. The reversal of 21314475691 is 19657441312.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21314475691 - 2⁷ = 21314475563 is a prime.

It is not a weakly prime, because it can be changed into another prime (21314475991) 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 as a sum of consecutive naturals, namely, 10657237845 + 10657237846.

It is an arithmetic number, because the mean of its divisors is an integer number (10657237846).

Almost surely, 2^21314475691 is an apocalyptic number.

21314475691 is a deficient number, since it is larger than the sum of its proper divisors (1).

21314475691 is an equidigital number, since it uses as much as digits as its factorization.

21314475691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 43.

The spelling of 21314475691 in words is "twenty-one billion, three hundred fourteen million, four hundred seventy-five thousand, six hundred ninety-one".