261736320 has 128 divisors (see below), whose sum is σ = 870704640. Its totient is φ = 66750464.

The previous prime is 261736291. The next prime is 261736357. The reversal of 261736320 is 23637162.

261736320 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 (128).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41197 + ... + 47123.

It is an arithmetic number, because the mean of its divisors is an integer number (6802380).

Almost surely, 2^261736320 is an apocalyptic number.

261736320 is a gapful number since it is divisible by the number (20) 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 261736320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (435352320).

261736320 is an abundant number, since it is smaller than the sum of its proper divisors (608968320).

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

261736320 is a wasteful number, since it uses less digits than its factorization.

261736320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5972 (or 5960 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 30.

The square root of 261736320 is about 16178.2669034727. The cubic root of 261736320 is about 639.6680570306.

The spelling of 261736320 in words is "two hundred sixty-one million, seven hundred thirty-six thousand, three hundred twenty".