21208015161 has 16 divisors (see below), whose sum is σ = 31560184320. Its totient is φ = 14075270640.

The previous prime is 21208015141. The next prime is 21208015217. The reversal of 21208015161 is 16151080212.

It is not a de Polignac number, because 21208015161 - 2²¹ = 21205918009 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21208015141) 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, 1755150 + ... + 1767191.

It is an arithmetic number, because the mean of its divisors is an integer number (1972511520).

Almost surely, 2^21208015161 is an apocalyptic number.

It is an amenable number.

21208015161 is a deficient number, since it is larger than the sum of its proper divisors (10352169159).

21208015161 is a wasteful number, since it uses less digits than its factorization.

21208015161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3522573 (or 3522567 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

Adding to 21208015161 its reverse (16151080212), we get a palindrome (37359095373).

It can be divided in two parts, 212080151 and 61, that added together give a palindrome (212080212).

The spelling of 21208015161 in words is "twenty-one billion, two hundred eight million, fifteen thousand, one hundred sixty-one".