1211112220021 has 12 divisors (see below), whose sum is σ = 1332230437132. Its totient is φ = 1100177496000.

The previous prime is 1211112220009. The next prime is 1211112220057. The reversal of 1211112220021 is 1200222111121.

It can be written as a sum of positive squares in 2 ways, for example, as 616075859025 + 595036360996 = 784905^2 + 771386^2 .

It is not a de Polignac number, because 1211112220021 - 2⁷ = 1211112219893 is a prime.

It is a super-2 number, since 2×1211112220021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211112219977 and 1211112220004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211112221021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3628650 + ... + 3948331.

Almost surely, 2^{1211112220021} is an apocalyptic number.

1211112220021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211112220021 is a deficient number, since it is larger than the sum of its proper divisors (121118217111).

1211112220021 is a wasteful number, since it uses less digits than its factorization.

1211112220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7578324 (or 7578313 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1211112220021 its reverse (1200222111121), we get a palindrome (2411334331142).

The spelling of 1211112220021 in words is "one trillion, two hundred eleven billion, one hundred twelve million, two hundred twenty thousand, twenty-one".