1221002020020 has 48 divisors (see below), whose sum is σ = 3420425530368. Its totient is φ = 325446264960.

The previous prime is 1221002020019. The next prime is 1221002020061. The reversal of 1221002020020 is 200202001221.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 1221002019978 and 1221002020005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4693339 + ... + 4946658.

It is an arithmetic number, because the mean of its divisors is an integer number (71258865216).

Almost surely, 2^{1221002020020} is an apocalyptic number.

1221002020020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221002020020 is an abundant number, since it is smaller than the sum of its proper divisors (2199423510348).

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

1221002020020 is a wasteful number, since it uses less digits than its factorization.

1221002020020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9642120 (or 9642118 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 1221002020020 its reverse (200202001221), we get a palindrome (1421204021241).

The spelling of 1221002020020 in words is "one trillion, two hundred twenty-one billion, two million, twenty thousand, twenty".