1220121000021 has 64 divisors (see below), whose sum is σ = 2080089962496. Its totient is φ = 617665305600.

The previous prime is 1220121000017. The next prime is 1220121000071. The reversal of 1220121000021 is 1200001210221.

It is not a de Polignac number, because 1220121000021 - 2² = 1220121000017 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1220120999970 and 1220121000006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220121000071) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8289945 + ... + 8435841.

It is an arithmetic number, because the mean of its divisors is an integer number (32501405664).

Almost surely, 2^{1220121000021} is an apocalyptic number.

1220121000021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1220121000021 is a deficient number, since it is larger than the sum of its proper divisors (859968962475).

1220121000021 is a wasteful number, since it uses less digits than its factorization.

1220121000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146842.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 1220121000021 its reverse (1200001210221), we get a palindrome (2420122210242).

The spelling of 1220121000021 in words is "one trillion, two hundred twenty billion, one hundred twenty-one million, twenty-one", and thus it is an aban number.