1209901000 has 256 divisors, whose sum is σ = 3720038400. Its totient is φ = 356832000.

The previous prime is 1209900983. The next prime is 1209901001. The reversal of 1209901000 is 1099021.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (1209901001) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1462587 + ... + 1463413.

It is an arithmetic number, because the mean of its divisors is an integer number (14531400).

Almost surely, 2^1209901000 is an apocalyptic number.

1209901000 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 1209901000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1860019200).

1209901000 is an abundant number, since it is smaller than the sum of its proper divisors (2510137400).

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

1209901000 is a wasteful number, since it uses less digits than its factorization.

1209901000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 885 (or 871 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 1209901000 is about 34783.6312077966. The cubic root of 1209901000 is about 1065.5731740948.

It can be divided in two parts, 1209 and 901000, that added together give a palindrome (902209).

The spelling of 1209901000 in words is "one billion, two hundred nine million, nine hundred one thousand".