2161621518 has 32 divisors (see below), whose sum is σ = 4942404864. Its totient is φ = 617411712.

The previous prime is 2161621499. The next prime is 2161621529. The reversal of 2161621518 is 8151261612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 176221 + ... + 188087.

It is an arithmetic number, because the mean of its divisors is an integer number (154450152).

Almost surely, 2^2161621518 is an apocalyptic number.

2161621518 is an abundant number, since it is smaller than the sum of its proper divisors (2780783346).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2161621518 is a wasteful number, since it uses less digits than its factorization.

2161621518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16216.

The product of its digits is 5760, while the sum is 33.

The square root of 2161621518 is about 46493.2416378983. The cubic root of 2161621518 is about 1292.9842011314.

It can be divided in two parts, 21616 and 21518, that added together give a palindrome (43134).

The spelling of 2161621518 in words is "two billion, one hundred sixty-one million, six hundred twenty-one thousand, five hundred eighteen".