21161665650567 has 8 divisors (see below), whose sum is σ = 30385981447024. Its totient is φ = 13022563477248.

The previous prime is 21161665650533. The next prime is 21161665650577. The reversal of 21161665650567 is 76505656616112.

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

It is not a de Polignac number, because 21161665650567 - 2¹⁰ = 21161665649543 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 (21161665650577) 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, 271303405738 + ... + 271303405815.

It is an arithmetic number, because the mean of its divisors is an integer number (3798247680878).

Almost surely, 2^{21161665650567} is an apocalyptic number.

21161665650567 is a deficient number, since it is larger than the sum of its proper divisors (9224315796457).

21161665650567 is a wasteful number, since it uses less digits than its factorization.

21161665650567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 542606811569.

The product of its (nonzero) digits is 13608000, while the sum is 57.

The spelling of 21161665650567 in words is "twenty-one trillion, one hundred sixty-one billion, six hundred sixty-five million, six hundred fifty thousand, five hundred sixty-seven".