21564341067 has 16 divisors (see below), whose sum is σ = 30446945280. Its totient is φ = 13529158272.

The previous prime is 21564341059. The next prime is 21564341111. The reversal of 21564341067 is 76014346512.

It is a happy number.

It is not a de Polignac number, because 21564341067 - 2³ = 21564341059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21564341167) 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, 707178 + ... + 737040.

It is an arithmetic number, because the mean of its divisors is an integer number (1902934080).

Almost surely, 2^21564341067 is an apocalyptic number.

21564341067 is a deficient number, since it is larger than the sum of its proper divisors (8882604213).

21564341067 is a wasteful number, since it uses less digits than its factorization.

21564341067 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44042.

The product of its (nonzero) digits is 120960, while the sum is 39.

Adding to 21564341067 its reverse (76014346512), we get a palindrome (97578687579).

Subtracting 21564341067 from its reverse (76014346512), we obtain a palindrome (54450005445).

The spelling of 21564341067 in words is "twenty-one billion, five hundred sixty-four million, three hundred forty-one thousand, sixty-seven".