1261485984 has 144 divisors (see below), whose sum is σ = 3672012960. Its totient is φ = 378892800.

The previous prime is 1261485931. The next prime is 1261485997. The reversal of 1261485984 is 4895841621.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1521282 + ... + 1522110.

It is an arithmetic number, because the mean of its divisors is an integer number (25500090).

Almost surely, 2^1261485984 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1261485984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1836006480).

1261485984 is an abundant number, since it is smaller than the sum of its proper divisors (2410526976).

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

1261485984 is a wasteful number, since it uses less digits than its factorization.

1261485984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 995 (or 976 counting only the distinct ones).

The product of its digits is 552960, while the sum is 48.

The square root of 1261485984 is about 35517.4039591860. The cubic root of 1261485984 is about 1080.5067306572.

The spelling of 1261485984 in words is "one billion, two hundred sixty-one million, four hundred eighty-five thousand, nine hundred eighty-four".