1209957840 has 480 divisors, whose sum is σ = 5102173440. Its totient is φ = 250159104.

The previous prime is 1209957823. The next prime is 1209957863. The reversal of 1209957840 is 487599021.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3865524 + ... + 3865836.

It is an arithmetic number, because the mean of its divisors is an integer number (10629528).

Almost surely, 2^1209957840 is an apocalyptic number.

1209957840 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 1209957840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2551086720).

1209957840 is an abundant number, since it is smaller than the sum of its proper divisors (3892215600).

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

1209957840 is a wasteful number, since it uses less digits than its factorization.

1209957840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411 (or 402 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 1209957840 is about 34784.4482491817. The cubic root of 1209957840 is about 1065.5898603721.

The spelling of 1209957840 in words is "one billion, two hundred nine million, nine hundred fifty-seven thousand, eight hundred forty".