21420755167 has 32 divisors (see below), whose sum is σ = 25100734464. Its totient is φ = 17902684800.

The previous prime is 21420755159. The next prime is 21420755179. The reversal of 21420755167 is 76155702412.

21420755167 is an astonishing number since 21420755167 = 55167 + ... + 214207.

It is not a de Polignac number, because 21420755167 - 2³ = 21420755159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420755567) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21145353 + ... + 21146365.

It is an arithmetic number, because the mean of its divisors is an integer number (784397952).

Almost surely, 2^21420755167 is an apocalyptic number.

21420755167 is a deficient number, since it is larger than the sum of its proper divisors (3679979297).

21420755167 is a wasteful number, since it uses less digits than its factorization.

21420755167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1519.

The product of its (nonzero) digits is 117600, while the sum is 40.

The spelling of 21420755167 in words is "twenty-one billion, four hundred twenty million, seven hundred fifty-five thousand, one hundred sixty-seven".