1220120221021 has 16 divisors (see below), whose sum is σ = 1346269297968. Its totient is φ = 1098594547200.

The previous prime is 1220120220973. The next prime is 1220120221043. The reversal of 1220120221021 is 1201220210221.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 2198296996 + 1217921924025 = 46886^2 + 1103595^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220120221021 - 2³⁵ = 1185760482653 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1220120220986 and 1220120221004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220120221081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2755911 + ... + 3167851.

It is an arithmetic number, because the mean of its divisors is an integer number (84141831123).

Almost surely, 2^{1220120221021} is an apocalyptic number.

It is an amenable number.

1220120221021 is a deficient number, since it is larger than the sum of its proper divisors (126149076947).

1220120221021 is a wasteful number, since it uses less digits than its factorization.

1220120221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417552.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1220120221021 its reverse (1201220210221), we get a palindrome (2421340431242).

The spelling of 1220120221021 in words is "one trillion, two hundred twenty billion, one hundred twenty million, two hundred twenty-one thousand, twenty-one".