21455164167 has 16 divisors (see below), whose sum is σ = 29335914720. Its totient is φ = 13939673600.

The previous prime is 21455164151. The next prime is 21455164187. The reversal of 21455164167 is 76146155412.

It is a cyclic number.

It is not a de Polignac number, because 21455164167 - 2⁴ = 21455164151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455164127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23059 + ... + 208427.

It is an arithmetic number, because the mean of its divisors is an integer number (1833494670).

Almost surely, 2^21455164167 is an apocalyptic number.

21455164167 is a deficient number, since it is larger than the sum of its proper divisors (7880750553).

21455164167 is a wasteful number, since it uses less digits than its factorization.

21455164167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186354.

The product of its digits is 201600, while the sum is 42.

The spelling of 21455164167 in words is "twenty-one billion, four hundred fifty-five million, one hundred sixty-four thousand, one hundred sixty-seven".