1211021100090 has 48 divisors (see below), whose sum is σ = 3153305912328. Its totient is φ = 322461929088.

The previous prime is 1211021100067. The next prime is 1211021100109. The reversal of 1211021100090 is 900011201121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1122567797169 + 88453302921 = 1059513^2 + 297411^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9876877 + ... + 9998736.

Almost surely, 2^{1211021100090} is an apocalyptic number.

1211021100090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1211021100090 is an abundant number, since it is smaller than the sum of its proper divisors (1942284812238).

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

1211021100090 is a wasteful number, since it uses less digits than its factorization.

1211021100090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19876303 (or 19876300 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

The spelling of 1211021100090 in words is "one trillion, two hundred eleven billion, twenty-one million, one hundred thousand, ninety".