1231021000 has 256 divisors, whose sum is σ = 3457209600. Its totient is φ = 404992000.

The previous prime is 1231020929. The next prime is 1231021009. The reversal of 1231021000 is 1201321.

1231021000 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (1231021009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5422887 + ... + 5423113.

It is an arithmetic number, because the mean of its divisors is an integer number (13504725).

Almost surely, 2^1231021000 is an apocalyptic number.

1231021000 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 1231021000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1728604800).

1231021000 is an abundant number, since it is smaller than the sum of its proper divisors (2226188600).

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

1231021000 is a wasteful number, since it uses less digits than its factorization.

1231021000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 1231021000 is about 35085.9088524154. The cubic root of 1231021000 is about 1071.7376488206.

Adding to 1231021000 its reverse (1201321), we get a palindrome (1232222321).

The spelling of 1231021000 in words is "one billion, two hundred thirty-one million, twenty-one thousand".