1221122121012 has 18 divisors (see below), whose sum is σ = 3086725361538. Its totient is φ = 407040706992.

The previous prime is 1221122120987. The next prime is 1221122121029. The reversal of 1221122121012 is 2101212211221.

1221122121012 is a `hidden beast` number, since 1 + 221 + 1 + 221 + 210 + 12 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1172226297636 + 48895823376 = 1082694^2 + 221124^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×1221122121012² (a number of 25 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16960029423 + ... + 16960029494.

Almost surely, 2^{1221122121012} is an apocalyptic number.

1221122121012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221122121012 is an abundant number, since it is smaller than the sum of its proper divisors (1865603240526).

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

1221122121012 is a wasteful number, since it uses less digits than its factorization.

1221122121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33920058927 (or 33920058922 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1221122121012 its reverse (2101212211221), we get a palindrome (3322334332233).

The spelling of 1221122121012 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, one hundred twenty-one thousand, twelve".