21654495667 has 12 divisors (see below), whose sum is σ = 25192789776. Its totient is φ = 18558884400.

The previous prime is 21654495661. The next prime is 21654495673. The reversal of 21654495667 is 76659445612.

It is an interprime number because it is at equal distance from previous prime (21654495661) and next prime (21654495673).

It is a de Polignac number, because none of the positive numbers 2^k-21654495667 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21654495661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 536733 + ... + 575665.

It is an arithmetic number, because the mean of its divisors is an integer number (2099399148).

Almost surely, 2^21654495667 is an apocalyptic number.

21654495667 is a deficient number, since it is larger than the sum of its proper divisors (3538294109).

21654495667 is a wasteful number, since it uses less digits than its factorization.

21654495667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50298 (or 50291 counting only the distinct ones).

The product of its digits is 10886400, while the sum is 55.

The spelling of 21654495667 in words is "twenty-one billion, six hundred fifty-four million, four hundred ninety-five thousand, six hundred sixty-seven".