21021201111001 has 32 divisors (see below), whose sum is σ = 25898859786240. Its totient is φ = 16615060289856.

The previous prime is 21021201110993. The next prime is 21021201111013. The reversal of 21021201111001 is 10011110212012.

It is a happy number.

It is not a de Polignac number, because 21021201111001 - 2³ = 21021201110993 is a prime.

It is a super-2 number, since 2×21021201111001² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is not an unprimeable number, because it can be changed into a prime (21021201115001) 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, 356824590 + ... + 356883496.

It is an arithmetic number, because the mean of its divisors is an integer number (809339368320).

Almost surely, 2^{21021201111001} is an apocalyptic number.

It is an amenable number.

21021201111001 is a deficient number, since it is larger than the sum of its proper divisors (4877658675239).

21021201111001 is a wasteful number, since it uses less digits than its factorization.

21021201111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62893.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21021201111001 its reverse (10011110212012), we get a palindrome (31032311323013).

The spelling of 21021201111001 in words is "twenty-one trillion, twenty-one billion, two hundred one million, one hundred eleven thousand, one".