261521066 has 8 divisors (see below), whose sum is σ = 400628160. Its totient is φ = 127978348.

The previous prime is 261521041. The next prime is 261521087. The reversal of 261521066 is 660125162.

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, 1390976 + ... + 1391163.

It is an arithmetic number, because the mean of its divisors is an integer number (50078520).

Almost surely, 2^261521066 is an apocalyptic number.

261521066 is a deficient number, since it is larger than the sum of its proper divisors (139107094).

261521066 is a wasteful number, since it uses less digits than its factorization.

261521066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2782188.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 261521066 is about 16171.6129684086. The cubic root of 261521066 is about 639.4926529302.

The spelling of 261521066 in words is "two hundred sixty-one million, five hundred twenty-one thousand, sixty-six".