21012110001001 has 12 divisors (see below), whose sum is σ = 24549395086020. Its totient is φ = 17931732043680.

The previous prime is 21012110000983. The next prime is 21012110001007. The reversal of 21012110001001 is 10010001121012.

It can be written as a sum of positive squares in 2 ways, for example, as 11301033613401 + 9711076387600 = 3361701^2 + 3116260^2 .

It is not a de Polignac number, because 21012110001001 - 2²⁹ = 21011573130089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21012110001007) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 936273870 + ... + 936296311.

It is an arithmetic number, because the mean of its divisors is an integer number (2045782923835).

Almost surely, 2^{21012110001001} is an apocalyptic number.

It is an amenable number.

21012110001001 is a deficient number, since it is larger than the sum of its proper divisors (3537285085019).

21012110001001 is a wasteful number, since it uses less digits than its factorization.

21012110001001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1872570424 (or 1872570417 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21012110001001 its reverse (10010001121012), we get a palindrome (31022111122013).

The spelling of 21012110001001 in words is "twenty-one trillion, twelve billion, one hundred ten million, one thousand, one".