261509946 has 32 divisors (see below), whose sum is σ = 560027520. Its totient is φ = 81117696.

The previous prime is 261509923. The next prime is 261509951. The reversal of 261509946 is 649905162.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 261509898 and 261509907.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5326 + ... + 23481.

It is an arithmetic number, because the mean of its divisors is an integer number (17500860).

Almost surely, 2^261509946 is an apocalyptic number.

261509946 is an abundant number, since it is smaller than the sum of its proper divisors (298517574).

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

261509946 is a wasteful number, since it uses less digits than its factorization.

261509946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28918.

The product of its (nonzero) digits is 116640, while the sum is 42.

The square root of 261509946 is about 16171.2691524197. The cubic root of 261509946 is about 639.4835889579.

The spelling of 261509946 in words is "two hundred sixty-one million, five hundred nine thousand, nine hundred forty-six".