1201221020 has 48 divisors (see below), whose sum is σ = 2696960448. Its totient is φ = 447820800.

The previous prime is 1201221019. The next prime is 1201221029. The reversal of 1201221020 is 201221021.

1201221020 = T₃₉₂ + T₃₉₃ + ... + T₁₉₃₆.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1201220992 and 1201221010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201221029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17870 + ... + 52170.

It is an arithmetic number, because the mean of its divisors is an integer number (56186676).

Almost surely, 2^1201221020 is an apocalyptic number.

1201221020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1201221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1348480224).

1201221020 is an abundant number, since it is smaller than the sum of its proper divisors (1495739428).

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

1201221020 is a wasteful number, since it uses less digits than its factorization.

1201221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34430 (or 34428 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1201221020 is about 34658.6355761447. The cubic root of 1201221020 is about 1063.0188712741.

Adding to 1201221020 its reverse (201221021), we get a palindrome (1402442041).

Subtracting from 1201221020 its reverse (201221021), we obtain a palindrome (999999999).

The spelling of 1201221020 in words is "one billion, two hundred one million, two hundred twenty-one thousand, twenty".