21242243452401 has 18 divisors (see below), whose sum is σ = 30919251940850. Its totient is φ = 14053392512640.

The previous prime is 21242243452357. The next prime is 21242243452421. The reversal of 21242243452401 is 10425434224212.

21242243452401 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 2 + 243 + 4 + 5 + 2 + 401 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20998206464400 + 244036988001 = 4582380^2 + 494001^2 .

It is not a de Polignac number, because 21242243452401 - 2¹³ = 21242243444209 is a prime.

It is a super-4 number, since 4×21242243452401⁴ (a number of 54 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21242243452421) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 68613376 + ... + 68922273.

Almost surely, 2^{21242243452401} is an apocalyptic number.

It is an amenable number.

21242243452401 is a deficient number, since it is larger than the sum of its proper divisors (9677008488449).

21242243452401 is a wasteful number, since it uses less digits than its factorization.

21242243452401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137535917 (or 137535783 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 36.

Adding to 21242243452401 its reverse (10425434224212), we get a palindrome (31667677676613).

The spelling of 21242243452401 in words is "twenty-one trillion, two hundred forty-two billion, two hundred forty-three million, four hundred fifty-two thousand, four hundred one".