21228654165 has 8 divisors (see below), whose sum is σ = 33965846688. Its totient is φ = 11321948880.

The previous prime is 21228654163. The next prime is 21228654179. The reversal of 21228654165 is 56145682212.

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

It is not a de Polignac number, because 21228654165 - 2¹ = 21228654163 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21228654163) 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, 707621791 + ... + 707621820.

It is an arithmetic number, because the mean of its divisors is an integer number (4245730836).

Almost surely, 2^21228654165 is an apocalyptic number.

It is an amenable number.

21228654165 is a deficient number, since it is larger than the sum of its proper divisors (12737192523).

21228654165 is a wasteful number, since it uses less digits than its factorization.

21228654165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1415243619.

The product of its digits is 230400, while the sum is 42.

The spelling of 21228654165 in words is "twenty-one billion, two hundred twenty-eight million, six hundred fifty-four thousand, one hundred sixty-five".