21123404501201 has 16 divisors (see below), whose sum is σ = 22752693573120. Its totient is φ = 19539761303040.

The previous prime is 21123404501159. The next prime is 21123404501233. The reversal of 21123404501201 is 10210540432112.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21123404501201 - 2³⁸ = 20848526594257 is a prime.

It is a super-2 number, since 2×21123404501201² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21123404521201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41547545 + ... + 42052886.

It is an arithmetic number, because the mean of its divisors is an integer number (1422043348320).

Almost surely, 2^{21123404501201} is an apocalyptic number.

It is an amenable number.

21123404501201 is a deficient number, since it is larger than the sum of its proper divisors (1629289071919).

21123404501201 is a wasteful number, since it uses less digits than its factorization.

21123404501201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83600704.

The product of its (nonzero) digits is 1920, while the sum is 26.

Adding to 21123404501201 its reverse (10210540432112), we get a palindrome (31333944933313).

The spelling of 21123404501201 in words is "twenty-one trillion, one hundred twenty-three billion, four hundred four million, five hundred one thousand, two hundred one".