261049966 has 4 divisors (see below), whose sum is σ = 391574952. Its totient is φ = 130524982.

The previous prime is 261049961. The next prime is 261050003. The reversal of 261049966 is 669940162.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261049961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65262490 + ... + 65262493.

It is an arithmetic number, because the mean of its divisors is an integer number (97893738).

Almost surely, 2^261049966 is an apocalyptic number.

261049966 is a deficient number, since it is larger than the sum of its proper divisors (130524986).

261049966 is a wasteful number, since it uses less digits than its factorization.

261049966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130524985.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 261049966 is about 16157.0407562771. The cubic root of 261049966 is about 639.1084314056.

The spelling of 261049966 in words is "two hundred sixty-one million, forty-nine thousand, nine hundred sixty-six".