261381024 has 144 divisors (see below), whose sum is σ = 804192480. Its totient is φ = 80248320.

The previous prime is 261380989. The next prime is 261381037. The reversal of 261381024 is 420183162.

261381024 is a `hidden beast` number, since 261 + 381 + 0 + 24 = 666.

261381024 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 201819 + ... + 203109.

It is an arithmetic number, because the mean of its divisors is an integer number (5584670).

Almost surely, 2^261381024 is an apocalyptic number.

261381024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261381024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (402096240).

261381024 is an abundant number, since it is smaller than the sum of its proper divisors (542811456).

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

261381024 is a wasteful number, since it uses less digits than its factorization.

261381024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1363 (or 1352 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 261381024 is about 16167.2825174796. The cubic root of 261381024 is about 639.3784851735.

The spelling of 261381024 in words is "two hundred sixty-one million, three hundred eighty-one thousand, twenty-four".