261727720 has 16 divisors (see below), whose sum is σ = 588887460. Its totient is φ = 104691072.

The previous prime is 261727709. The next prime is 261727747. The reversal of 261727720 is 27727162.

It can be written as a sum of positive squares in 2 ways, for example, as 261727684 + 36 = 16178^2 + 6^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3271557 + ... + 3271636.

Almost surely, 2^261727720 is an apocalyptic number.

261727720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261727720 is an abundant number, since it is smaller than the sum of its proper divisors (327159740).

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

261727720 is a wasteful number, since it uses less digits than its factorization.

261727720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6543204 (or 6543200 counting only the distinct ones).

The product of its (nonzero) digits is 16464, while the sum is 34.

The square root of 261727720 is about 16178.0011126220. The cubic root of 261727720 is about 639.6610509904.

The spelling of 261727720 in words is "two hundred sixty-one million, seven hundred twenty-seven thousand, seven hundred twenty".