261984450 has 192 divisors, whose sum is σ = 847445760. Its totient is φ = 51978240.

The previous prime is 261984431. The next prime is 261984451. The reversal of 261984450 is 54489162.

261984450 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a junction number, because it is equal to n+sod(n) for n = 261984399 and 261984408.

It is not an unprimeable number, because it can be changed into a prime (261984451) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 231486 + ... + 232614.

It is an arithmetic number, because the mean of its divisors is an integer number (4413780).

Almost surely, 2^261984450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261984450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (423722880).

261984450 is an abundant number, since it is smaller than the sum of its proper divisors (585461310).

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

261984450 is a wasteful number, since it uses less digits than its factorization.

261984450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1181 (or 1176 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

The square root of 261984450 is about 16185.9337080071. The cubic root of 261984450 is about 639.8701315265.

The spelling of 261984450 in words is "two hundred sixty-one million, nine hundred eighty-four thousand, four hundred fifty".