1201021020 has 120 divisors (see below), whose sum is σ = 3806987184. Its totient is φ = 316929024.

The previous prime is 1201021013. The next prime is 1201021037. The reversal of 1201021020 is 201201021.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 1201020993 and 1201021011.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 153319 + ... + 160961.

Almost surely, 2^1201021020 is an apocalyptic number.

1201021020 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 1201021020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1903493592).

1201021020 is an abundant number, since it is smaller than the sum of its proper divisors (2605966164).

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

1201021020 is a wasteful number, since it uses less digits than its factorization.

1201021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7761 (or 7750 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1201021020 is about 34655.7501722297. The cubic root of 1201021020 is about 1062.9598714256.

Adding to 1201021020 its reverse (201201021), we get a palindrome (1402222041).

The spelling of 1201021020 in words is "one billion, two hundred one million, twenty-one thousand, twenty".