1265897850 has 144 divisors (see below), whose sum is σ = 3778552800. Its totient is φ = 279323520.

The previous prime is 1265897849. The next prime is 1265897861. The reversal of 1265897850 is 587985621.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1265897793 and 1265897802.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 210181 + ... + 216119.

It is an arithmetic number, because the mean of its divisors is an integer number (26239950).

Almost surely, 2^1265897850 is an apocalyptic number.

1265897850 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1265897850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1889276400).

1265897850 is an abundant number, since it is smaller than the sum of its proper divisors (2512654950).

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

1265897850 is a wasteful number, since it uses less digits than its factorization.

1265897850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5997 (or 5985 counting only the distinct ones).

The product of its (nonzero) digits is 1209600, while the sum is 51.

The square root of 1265897850 is about 35579.4582589449. The cubic root of 1265897850 is about 1081.7649040555.

The spelling of 1265897850 in words is "one billion, two hundred sixty-five million, eight hundred ninety-seven thousand, eight hundred fifty".