1211021000021 has 16 divisors (see below), whose sum is σ = 1466342559360. Its totient is φ = 976354529280.

The previous prime is 1211020999961. The next prime is 1211021000029. The reversal of 1211021000021 is 1200001201121.

It is a cyclic number.

It is not a de Polignac number, because 1211021000021 - 2²² = 1211016805717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1211020999966 and 1211021000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211021000029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2950220 + ... + 3335541.

It is an arithmetic number, because the mean of its divisors is an integer number (91646409960).

Almost surely, 2^{1211021000021} is an apocalyptic number.

It is an amenable number.

1211021000021 is a deficient number, since it is larger than the sum of its proper divisors (255321559339).

1211021000021 is a wasteful number, since it uses less digits than its factorization.

1211021000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6287404.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 1211021000021 its reverse (1200001201121), we get a palindrome (2411022201142).

The spelling of 1211021000021 in words is "one trillion, two hundred eleven billion, twenty-one million, twenty-one", and thus it is an aban number.