1211100101021 has 12 divisors (see below), whose sum is σ = 1330895120820. Its totient is φ = 1100553431040.

The previous prime is 1211100100993. The next prime is 1211100101027. The reversal of 1211100101021 is 1201010011121.

It can be written as a sum of positive squares in 6 ways, for example, as 235181352025 + 975918748996 = 484955^2 + 987886^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1211100101021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211100100993 and 1211100101011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211100101027) 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, 72244340 + ... + 72261101.

It is an arithmetic number, because the mean of its divisors is an integer number (110907926735).

Almost surely, 2^{1211100101021} is an apocalyptic number.

It is an amenable number.

1211100101021 is a deficient number, since it is larger than the sum of its proper divisors (119795019799).

1211100101021 is a wasteful number, since it uses less digits than its factorization.

1211100101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144505504 (or 144505487 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 1211100101021 its reverse (1201010011121), we get a palindrome (2412110112142).

The spelling of 1211100101021 in words is "one trillion, two hundred eleven billion, one hundred million, one hundred one thousand, twenty-one".