1211121220020 has 24 divisors (see below), whose sum is σ = 3391139416224. Its totient is φ = 322965658656.

The previous prime is 1211121220009. The next prime is 1211121220031. The reversal of 1211121220020 is 200221211121.

It is an interprime number because it is at equal distance from previous prime (1211121220009) and next prime (1211121220031).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 10092676774 + ... + 10092676893.

It is an arithmetic number, because the mean of its divisors is an integer number (141297475676).

Almost surely, 2^{1211121220020} is an apocalyptic number.

1211121220020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211121220020 is an abundant number, since it is smaller than the sum of its proper divisors (2180018196204).

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

1211121220020 is a wasteful number, since it uses less digits than its factorization.

1211121220020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20185353679 (or 20185353677 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1211121220020 its reverse (200221211121), we get a palindrome (1411342431141).

The spelling of 1211121220020 in words is "one trillion, two hundred eleven billion, one hundred twenty-one million, two hundred twenty thousand, twenty".