261020340 has 192 divisors, whose sum is σ = 935424000. Its totient is φ = 59190912.

The previous prime is 261020339. The next prime is 261020351. The reversal of 261020340 is 43020162.

It is a happy number.

261020340 is a `hidden beast` number, since 2 + 610 + 20 + 34 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 752047 + ... + 752393.

It is an arithmetic number, because the mean of its divisors is an integer number (4872000).

Almost surely, 2^261020340 is an apocalyptic number.

261020340 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 261020340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (467712000).

261020340 is an abundant number, since it is smaller than the sum of its proper divisors (674403660).

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

261020340 is a wasteful number, since it uses less digits than its factorization.

261020340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571 (or 563 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 261020340 is about 16156.1239163359. The cubic root of 261020340 is about 639.0842534765.

The spelling of 261020340 in words is "two hundred sixty-one million, twenty thousand, three hundred forty".