261823824 has 30 divisors (see below), whose sum is σ = 732743466. Its totient is φ = 87274560.

The previous prime is 261823823. The next prime is 261823829. The reversal of 261823824 is 428328162.

261823824 is a `hidden beast` number, since 2 + 618 + 2 + 38 + 2 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 166410000 + 95413824 = 12900^2 + 9768^2 .

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261823823) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 908967 + ... + 909254.

Almost surely, 2^261823824 is an apocalyptic number.

261823824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

261823824 is an abundant number, since it is smaller than the sum of its proper divisors (470919642).

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

261823824 is a wasteful number, since it uses less digits than its factorization.

261823824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1818235 (or 1818226 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 261823824 is about 16180.9710462630. The cubic root of 261823824 is about 639.7393339517.

The spelling of 261823824 in words is "two hundred sixty-one million, eight hundred twenty-three thousand, eight hundred twenty-four".