21611723374206 has 24 divisors (see below), whose sum is σ = 53514743593584. Its totient is φ = 6174778106880.

The previous prime is 21611723374201. The next prime is 21611723374223. The reversal of 21611723374206 is 60247332711612.

It is a happy number.

21611723374206 is a `hidden beast` number, since 2 + 1 + 6 + 1 + 1 + 72 + 3 + 374 + 206 = 666.

It is a super-2 number, since 2×21611723374206² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21611723374201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85760806915 + ... + 85760807166.

It is an arithmetic number, because the mean of its divisors is an integer number (2229780983066).

Almost surely, 2^{21611723374206} is an apocalyptic number.

21611723374206 is an abundant number, since it is smaller than the sum of its proper divisors (31903020219378).

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

21611723374206 is a wasteful number, since it uses less digits than its factorization.

21611723374206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171521614096 (or 171521614093 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The spelling of 21611723374206 in words is "twenty-one trillion, six hundred eleven billion, seven hundred twenty-three million, three hundred seventy-four thousand, two hundred six".