21221534462065 has 16 divisors (see below), whose sum is σ = 29652947347968. Its totient is φ = 14277345016896.

The previous prime is 21221534462003. The next prime is 21221534462119. The reversal of 21221534462065 is 56026443512212.

It is a cyclic number.

It is not a de Polignac number, because 21221534462065 - 2¹⁵ = 21221534429297 is a prime.

It is a super-2 number, since 2×21221534462065² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5720088297 + ... + 5720092006.

It is an arithmetic number, because the mean of its divisors is an integer number (1853309209248).

Almost surely, 2^{21221534462065} is an apocalyptic number.

It is an amenable number.

21221534462065 is a deficient number, since it is larger than the sum of its proper divisors (8431412885903).

21221534462065 is a wasteful number, since it uses less digits than its factorization.

21221534462065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11440180368.

The product of its (nonzero) digits is 691200, while the sum is 43.

Adding to 21221534462065 its reverse (56026443512212), we get a palindrome (77247977974277).

The spelling of 21221534462065 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred thirty-four million, four hundred sixty-two thousand, sixty-five".