261298380 has 288 divisors, whose sum is σ = 911941632. Its totient is φ = 55641600.

The previous prime is 261298369. The next prime is 261298399. The reversal of 261298380 is 83892162.

It is a happy number.

261298380 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4283550 + ... + 4283610.

It is an arithmetic number, because the mean of its divisors is an integer number (3166464).

Almost surely, 2^261298380 is an apocalyptic number.

261298380 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 261298380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (455970816).

261298380 is an abundant number, since it is smaller than the sum of its proper divisors (650643252).

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

261298380 is a wasteful number, since it uses less digits than its factorization.

261298380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 156 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 261298380 is about 16164.7264127792. The cubic root of 261298380 is about 639.3110913936.

The spelling of 261298380 in words is "two hundred sixty-one million, two hundred ninety-eight thousand, three hundred eighty".