21623522135065 has 8 divisors (see below), whose sum is σ = 26205139696968. Its totient is φ = 17127542284800.

The previous prime is 21623522135057. The next prime is 21623522135081. The reversal of 21623522135065 is 56053122532612.

It can be written as a sum of positive squares in 4 ways, for example, as 2907308036889 + 18716214098176 = 1705083^2 + 4326224^2 .

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

It is not a de Polignac number, because 21623522135065 - 2³ = 21623522135057 is a prime.

It is a super-2 number, since 2×21623522135065² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21409427352 + ... + 21409428361.

It is an arithmetic number, because the mean of its divisors is an integer number (3275642462121).

Almost surely, 2^{21623522135065} is an apocalyptic number.

It is an amenable number.

21623522135065 is a deficient number, since it is larger than the sum of its proper divisors (4581617561903).

21623522135065 is a wasteful number, since it uses less digits than its factorization.

21623522135065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42818855819.

The product of its (nonzero) digits is 648000, while the sum is 43.

Adding to 21623522135065 its reverse (56053122532612), we get a palindrome (77676644667677).

The spelling of 21623522135065 in words is "twenty-one trillion, six hundred twenty-three billion, five hundred twenty-two million, one hundred thirty-five thousand, sixty-five".