261405512 has 16 divisors (see below), whose sum is σ = 496041840. Its totient is φ = 129127696.

The previous prime is 261405509. The next prime is 261405559. The reversal of 261405512 is 215504162.

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, 196178 + ... + 197505.

It is an arithmetic number, because the mean of its divisors is an integer number (31002615).

Almost surely, 2^261405512 is an apocalyptic number.

It is an amenable number.

261405512 is a deficient number, since it is larger than the sum of its proper divisors (234636328).

261405512 is a wasteful number, since it uses less digits than its factorization.

261405512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393772 (or 393768 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 261405512 is about 16168.0398317174. The cubic root of 261405512 is about 639.3984516974.

Adding to 261405512 its reverse (215504162), we get a palindrome (476909674).

The spelling of 261405512 in words is "two hundred sixty-one million, four hundred five thousand, five hundred twelve".