21216601261161 has 24 divisors (see below), whose sum is σ = 30681924049920. Its totient is φ = 14127918781536.

The previous prime is 21216601261153. The next prime is 21216601261231. The reversal of 21216601261161 is 16116210661212.

21216601261161 is a `hidden beast` number, since 2 + 1 + 2 + 16 + 601 + 26 + 1 + 16 + 1 = 666.

It is not a de Polignac number, because 21216601261161 - 2³ = 21216601261153 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21216601221161) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50257815 + ... + 50678211.

It is an arithmetic number, because the mean of its divisors is an integer number (1278413502080).

Almost surely, 2^{21216601261161} is an apocalyptic number.

It is an amenable number.

21216601261161 is a deficient number, since it is larger than the sum of its proper divisors (9465322788759).

21216601261161 is a wasteful number, since it uses less digits than its factorization.

21216601261161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426925 (or 426922 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The spelling of 21216601261161 in words is "twenty-one trillion, two hundred sixteen billion, six hundred one million, two hundred sixty-one thousand, one hundred sixty-one".