1210020000021 has 24 divisors (see below), whose sum is σ = 2102624563520. Its totient is φ = 655048420416.

The previous prime is 1210019999987. The next prime is 1210020000031. The reversal of 1210020000021 is 1200000200121.

It is not a de Polignac number, because 1210020000021 - 2¹¹ = 1210019997973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1210019999958 and 1210020000012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210020000031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 505437400 + ... + 505439793.

Almost surely, 2^{1210020000021} is an apocalyptic number.

It is an amenable number.

1210020000021 is a deficient number, since it is larger than the sum of its proper divisors (892604563499).

1210020000021 is a wasteful number, since it uses less digits than its factorization.

1210020000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010877225 (or 1010877222 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 1210020000021 its reverse (1200000200121), we get a palindrome (2410020200142).

The spelling of 1210020000021 in words is "one trillion, two hundred ten billion, twenty million, twenty-one", and thus it is an aban number.