21615006161 has 8 divisors (see below), whose sum is σ = 24703801920. Its totient is φ = 18526444848.

The previous prime is 21615006139. The next prime is 21615006221. The reversal of 21615006161 is 16160051612.

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

It is a cyclic number.

It is not a de Polignac number, because 21615006161 - 2¹⁴ = 21614989777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21615006761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 241235 + ... + 318471.

It is an arithmetic number, because the mean of its divisors is an integer number (3087975240).

Almost surely, 2^21615006161 is an apocalyptic number.

It is an amenable number.

21615006161 is a deficient number, since it is larger than the sum of its proper divisors (3088795759).

21615006161 is an equidigital number, since it uses as much as digits as its factorization.

21615006161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117223.

The product of its (nonzero) digits is 2160, while the sum is 29.

Adding to 21615006161 its reverse (16160051612), we get a palindrome (37775057773).

The spelling of 21615006161 in words is "twenty-one billion, six hundred fifteen million, six thousand, one hundred sixty-one".