261655210 has 8 divisors (see below), whose sum is σ = 470979396. Its totient is φ = 104662080.

The previous prime is 261655193. The next prime is 261655237. The reversal of 261655210 is 12556162.

261655210 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 215238241 + 46416969 = 14671^2 + 6813^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 13082751 + ... + 13082770.

Almost surely, 2^261655210 is an apocalyptic number.

261655210 is a deficient number, since it is larger than the sum of its proper divisors (209324186).

261655210 is a wasteful number, since it uses less digits than its factorization.

261655210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26165528.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 261655210 is about 16175.7599512357. The cubic root of 261655210 is about 639.6019741927.

It can be divided in two parts, 26165 and 5210, that added together give a triangular number (31375 = T₂₅₀).

The spelling of 261655210 in words is "two hundred sixty-one million, six hundred fifty-five thousand, two hundred ten".