261289950 has 48 divisors (see below), whose sum is σ = 657696000. Its totient is φ = 68634720.

The previous prime is 261289933. The next prime is 261289969. The reversal of 261289950 is 59982162.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2950 + ... + 23049.

It is an arithmetic number, because the mean of its divisors is an integer number (13702000).

Almost surely, 2^261289950 is an apocalyptic number.

261289950 is an abundant number, since it is smaller than the sum of its proper divisors (396406050).

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

261289950 is a wasteful number, since it uses less digits than its factorization.

261289950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26081 (or 26076 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 42.

The square root of 261289950 is about 16164.4656577321. The cubic root of 261289950 is about 639.3042161750.

The spelling of 261289950 in words is "two hundred sixty-one million, two hundred eighty-nine thousand, nine hundred fifty".