16265165621 has 4 divisors (see below), whose sum is σ = 16267361292. Its totient is φ = 16262969952.

The previous prime is 16265165611. The next prime is 16265165629. The reversal of 16265165621 is 12656156261.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8221048900 + 8044116721 = 90670^2 + 89689^2 .

It is a cyclic number.

It is not a de Polignac number, because 16265165621 - 2⁶ = 16265165557 is a prime.

It is a super-2 number, since 2×16265165621² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16265165629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1086686 + ... + 1101551.

It is an arithmetic number, because the mean of its divisors is an integer number (4066840323).

Almost surely, 2^16265165621 is an apocalyptic number.

It is an amenable number.

16265165621 is a deficient number, since it is larger than the sum of its proper divisors (2195671).

16265165621 is an equidigital number, since it uses as much as digits as its factorization.

16265165621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2195670.

The product of its digits is 129600, while the sum is 41.

The spelling of 16265165621 in words is "sixteen billion, two hundred sixty-five million, one hundred sixty-five thousand, six hundred twenty-one".