1211210021000 has 128 divisors (see below), whose sum is σ = 3343610050560. Its totient is φ = 401876064000.

The previous prime is 1211210020991. The next prime is 1211210021009. The reversal of 1211210021000 is 1200121121.

It is an interprime number because it is at equal distance from previous prime (1211210020991) and next prime (1211210021009).

It is not an unprimeable number, because it can be changed into a prime (1211210021009) 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, 2573807 + ... + 3007806.

It is an arithmetic number, because the mean of its divisors is an integer number (26121953520).

Almost surely, 2^{1211210021000} is an apocalyptic number.

1211210021000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211210021000 is an abundant number, since it is smaller than the sum of its proper divisors (2132400029560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211210021000 is a wasteful number, since it uses less digits than its factorization.

1211210021000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5581672 (or 5581658 counting only the distinct ones).

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

Adding to 1211210021000 its reverse (1200121121), we get a palindrome (1212410142121).

The spelling of 1211210021000 in words is "one trillion, two hundred eleven billion, two hundred ten million, twenty-one thousand".