1261008500 has 24 divisors (see below), whose sum is σ = 2754043656. Its totient is φ = 504403200.

The previous prime is 1261008461. The next prime is 1261008517. The reversal of 1261008500 is 58001621.

It can be written as a sum of positive squares in 4 ways, for example, as 103103716 + 1157904784 = 10154^2 + 34028^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1260509 + ... + 1261508.

It is an arithmetic number, because the mean of its divisors is an integer number (114751819).

Almost surely, 2^1261008500 is an apocalyptic number.

1261008500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1261008500 is an abundant number, since it is smaller than the sum of its proper divisors (1493035156).

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

1261008500 is a wasteful number, since it uses less digits than its factorization.

1261008500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2522036 (or 2522024 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 1261008500 is about 35510.6814916301. The cubic root of 1261008500 is about 1080.3703862216.

The spelling of 1261008500 in words is "one billion, two hundred sixty-one million, eight thousand, five hundred".