21216223653201 has 6 divisors (see below), whose sum is σ = 30645656387970. Its totient is φ = 14144149102128.

The previous prime is 21216223653151. The next prime is 21216223653239. The reversal of 21216223653201 is 10235632261212.

21216223653201 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 622 + 3 + 6 + 5 + 3 + 20 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20323425438801 + 892798214400 = 4508151^2 + 944880^2 .

It is not a de Polignac number, because 21216223653201 - 2²³ = 21216215264593 is a prime.

It is a super-2 number, since 2×21216223653201² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21216223653901) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1178679091836 + ... + 1178679091853.

It is an arithmetic number, because the mean of its divisors is an integer number (5107609397995).

Almost surely, 2^{21216223653201} is an apocalyptic number.

It is an amenable number.

21216223653201 is a deficient number, since it is larger than the sum of its proper divisors (9429432734769).

21216223653201 is a wasteful number, since it uses less digits than its factorization.

21216223653201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2357358183695 (or 2357358183692 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 21216223653201 in words is "twenty-one trillion, two hundred sixteen billion, two hundred twenty-three million, six hundred fifty-three thousand, two hundred one".