1211020021000 has 32 divisors (see below), whose sum is σ = 2833786851480. Its totient is φ = 484408008000.

The previous prime is 1211020020949. The next prime is 1211020021019. The reversal of 1211020021000 is 1200201121.

It can be written as a sum of positive squares in 4 ways, for example, as 652673325924 + 558346695076 = 807882^2 + 747226^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 605509011 + ... + 605511010.

Almost surely, 2^{1211020021000} is an apocalyptic number.

1211020021000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211020021000 is an abundant number, since it is smaller than the sum of its proper divisors (1622766830480).

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

1211020021000 is a wasteful number, since it uses less digits than its factorization.

1211020021000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1211020042 (or 1211020028 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 1211020021000 its reverse (1200201121), we get a palindrome (1212220222121).

The spelling of 1211020021000 in words is "one trillion, two hundred eleven billion, twenty million, twenty-one thousand".