21661032235345 has 32 divisors (see below), whose sum is σ = 27844093630080. Its totient is φ = 16119868216320.

The previous prime is 21661032235343. The next prime is 21661032235369. The reversal of 21661032235345 is 54353223016612.

It is not a de Polignac number, because 21661032235345 - 2¹ = 21661032235343 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21661032235343) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1811055 + ... + 6826564.

It is an arithmetic number, because the mean of its divisors is an integer number (870127925940).

Almost surely, 2^{21661032235345} is an apocalyptic number.

It is an amenable number.

21661032235345 is a deficient number, since it is larger than the sum of its proper divisors (6183061394735).

21661032235345 is a wasteful number, since it uses less digits than its factorization.

21661032235345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8637985.

The product of its (nonzero) digits is 777600, while the sum is 43.

The spelling of 21661032235345 in words is "twenty-one trillion, six hundred sixty-one billion, thirty-two million, two hundred thirty-five thousand, three hundred forty-five".