21661616167 has 8 divisors (see below), whose sum is σ = 22349701440. Its totient is φ = 20983878240.

The previous prime is 21661616111. The next prime is 21661616191. The reversal of 21661616167 is 76161616612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21661616167 - 2²³ = 21653227559 is a prime.

It is a super-2 number, since 2×21661616167² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21661616567) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2582584 + ... + 2590957.

It is an arithmetic number, because the mean of its divisors is an integer number (2793712680).

Almost surely, 2^21661616167 is an apocalyptic number.

21661616167 is a deficient number, since it is larger than the sum of its proper divisors (688085273).

21661616167 is an equidigital number, since it uses as much as digits as its factorization.

21661616167 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5173673.

The product of its digits is 108864, while the sum is 43.

The spelling of 21661616167 in words is "twenty-one billion, six hundred sixty-one million, six hundred sixteen thousand, one hundred sixty-seven".