1209921008 has 20 divisors (see below), whose sum is σ = 2482117920. Its totient is φ = 569374464.

The previous prime is 1209921001. The next prime is 1209921017. The reversal of 1209921008 is 8001299021.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1209921001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2223848 + ... + 2224391.

It is an arithmetic number, because the mean of its divisors is an integer number (124105896).

Almost surely, 2^1209921008 is an apocalyptic number.

It is an amenable number.

1209921008 is an abundant number, since it is smaller than the sum of its proper divisors (1272196912).

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

1209921008 is a wasteful number, since it uses less digits than its factorization.

1209921008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4448264 (or 4448258 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 1209921008 is about 34783.9188131527. The cubic root of 1209921008 is about 1065.5790478179.

The spelling of 1209921008 in words is "one billion, two hundred nine million, nine hundred twenty-one thousand, eight".