1220021312136 has 128 divisors (see below), whose sum is σ = 3344895734400. Its totient is φ = 367755264000.

The previous prime is 1220021312123. The next prime is 1220021312161. The reversal of 1220021312136 is 6312131200221.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59096376 + ... + 59117016.

It is an arithmetic number, because the mean of its divisors is an integer number (26131997925).

Almost surely, 2^{1220021312136} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1220021312136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1672447867200).

1220021312136 is an abundant number, since it is smaller than the sum of its proper divisors (2124874422264).

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

1220021312136 is a wasteful number, since it uses less digits than its factorization.

1220021312136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21831 (or 21827 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

Adding to 1220021312136 its reverse (6312131200221), we get a palindrome (7532152512357).

The spelling of 1220021312136 in words is "one trillion, two hundred twenty billion, twenty-one million, three hundred twelve thousand, one hundred thirty-six".