261391950 has 36 divisors (see below), whose sum is σ = 702274248. Its totient is φ = 69704400.

The previous prime is 261391943. The next prime is 261391951. The reversal of 261391950 is 59193162.

261391950 is a `hidden beast` number, since 261 + 391 + 9 + 5 + 0 = 666.

261391950 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261391951) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 289986 + ... + 290885.

It is an arithmetic number, because the mean of its divisors is an integer number (19507618).

Almost surely, 2^261391950 is an apocalyptic number.

261391950 is an abundant number, since it is smaller than the sum of its proper divisors (440882298).

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

261391950 is a wasteful number, since it uses less digits than its factorization.

261391950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580889 (or 580881 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 261391950 is about 16167.6204186021. The cubic root of 261391950 is about 639.3873939457.

The spelling of 261391950 in words is "two hundred sixty-one million, three hundred ninety-one thousand, nine hundred fifty".