261678582 has 48 divisors (see below), whose sum is σ = 626004288. Its totient is φ = 78336240.

The previous prime is 261678581. The next prime is 261678619. The reversal of 261678582 is 285876162.

261678582 is a `hidden beast` number, since 2 + 6 + 1 + 67 + 8 + 582 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261678581) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8473 + ... + 24395.

It is an arithmetic number, because the mean of its divisors is an integer number (13041756).

Almost surely, 2^261678582 is an apocalyptic number.

261678582 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 261678582, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (313002144).

261678582 is an abundant number, since it is smaller than the sum of its proper divisors (364325706).

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

261678582 is a wasteful number, since it uses less digits than its factorization.

261678582 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16025 (or 16022 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 261678582 is about 16176.4823741134. The cubic root of 261678582 is about 639.6210174879.

The spelling of 261678582 in words is "two hundred sixty-one million, six hundred seventy-eight thousand, five hundred eighty-two".