1261165824 has 108 divisors (see below), whose sum is σ = 3650142496. Its totient is φ = 418784256.

The previous prime is 1261165823. The next prime is 1261165837. The reversal of 1261165824 is 4285611621.

It is a happy number.

1261165824 is a `hidden beast` number, since 1 + 2 + 61 + 16 + 582 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261165823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 706437 + ... + 708219.

Almost surely, 2^1261165824 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 1261165824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1825071248).

1261165824 is an abundant number, since it is smaller than the sum of its proper divisors (2388976672).

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

1261165824 is a wasteful number, since it uses less digits than its factorization.

1261165824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2112 (or 2095 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 1261165824 is about 35512.8965870147. The cubic root of 1261165824 is about 1080.4153135219.

The spelling of 1261165824 in words is "one billion, two hundred sixty-one million, one hundred sixty-five thousand, eight hundred twenty-four".