261728424 has 48 divisors (see below), whose sum is σ = 709892820. Its totient is φ = 87114240.

The previous prime is 261728419. The next prime is 261728429. The reversal of 261728424 is 424827162.

261728424 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (261728419) and next prime (261728429).

It can be written as a sum of positive squares in 2 ways, for example, as 259532100 + 2196324 = 16110^2 + 1482^2 .

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

It is not an unprimeable number, because it can be changed into a prime (261728429) 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, 55104 + ... + 59664.

Almost surely, 2^261728424 is an apocalyptic number.

261728424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

261728424 is an abundant number, since it is smaller than the sum of its proper divisors (448164396).

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

261728424 is a wasteful number, since it uses less digits than its factorization.

261728424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5370 (or 5363 counting only the distinct ones).

The product of its digits is 43008, while the sum is 36.

The square root of 261728424 is about 16178.0228705488. The cubic root of 261728424 is about 639.6616245139.

It can be divided in two parts, 26172 and 8424, that added together give a square (34596 = 186²).

The spelling of 261728424 in words is "two hundred sixty-one million, seven hundred twenty-eight thousand, four hundred twenty-four".