1261670500 has 48 divisors (see below), whose sum is σ = 2759453424. Its totient is φ = 503942400.

The previous prime is 1261670483. The next prime is 1261670513. The reversal of 1261670500 is 50761621.

It can be written as a sum of positive squares in 8 ways, for example, as 807810084 + 453860416 = 28422^2 + 21304^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 467154 + ... + 469846.

It is an arithmetic number, because the mean of its divisors is an integer number (57488613).

Almost surely, 2^1261670500 is an apocalyptic number.

1261670500 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 1261670500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1379726712).

1261670500 is an abundant number, since it is smaller than the sum of its proper divisors (1497782924).

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

1261670500 is a wasteful number, since it uses less digits than its factorization.

1261670500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3649 (or 3637 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 1261670500 is about 35520.0014076576. The cubic root of 1261670500 is about 1080.5594095514.

The spelling of 1261670500 in words is "one billion, two hundred sixty-one million, six hundred seventy thousand, five hundred".