261927680 has 288 divisors, whose sum is σ = 791175168. Its totient is φ = 81100800.

The previous prime is 261927671. The next prime is 261927707. The reversal of 261927680 is 86729162.

It is a super-2 number, since 2×261927680² = 137212219100364800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6388460 + ... + 6388500.

It is an arithmetic number, because the mean of its divisors is an integer number (2747136).

Almost surely, 2^261927680 is an apocalyptic number.

261927680 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 261927680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (395587584).

261927680 is an abundant number, since it is smaller than the sum of its proper divisors (529247488).

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

261927680 is a wasteful number, since it uses less digits than its factorization.

261927680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 261927680 is about 16184.1799297956. The cubic root of 261927680 is about 639.8239098882.

The spelling of 261927680 in words is "two hundred sixty-one million, nine hundred twenty-seven thousand, six hundred eighty".