261506784 has 192 divisors, whose sum is σ = 906619392. Its totient is φ = 63897600.

The previous prime is 261506761. The next prime is 261506789. The reversal of 261506784 is 487605162.

261506784 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261506789) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 124624 + ... + 126704.

It is an arithmetic number, because the mean of its divisors is an integer number (4721976).

Almost surely, 2^261506784 is an apocalyptic number.

261506784 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 261506784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (453309696).

261506784 is an abundant number, since it is smaller than the sum of its proper divisors (645112608).

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

261506784 is a wasteful number, since it uses less digits than its factorization.

261506784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2129 (or 2121 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 261506784 is about 16171.1713861427. The cubic root of 261506784 is about 639.4810115476.

The spelling of 261506784 in words is "two hundred sixty-one million, five hundred six thousand, seven hundred eighty-four".