261630447 has 16 divisors (see below), whose sum is σ = 384413568. Its totient is φ = 157258080.

The previous prime is 261630433. The next prime is 261630469. The reversal of 261630447 is 744036162.

It is a happy number.

It is not a de Polignac number, because 261630447 - 2⁷ = 261630319 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261630427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76329 + ... + 79682.

It is an arithmetic number, because the mean of its divisors is an integer number (24025848).

Almost surely, 2^261630447 is an apocalyptic number.

261630447 is a deficient number, since it is larger than the sum of its proper divisors (122783121).

261630447 is a wasteful number, since it uses less digits than its factorization.

261630447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156070.

The product of its (nonzero) digits is 24192, while the sum is 33.

The square root of 261630447 is about 16174.9944976807. The cubic root of 261630447 is about 639.5817962858.

The spelling of 261630447 in words is "two hundred sixty-one million, six hundred thirty thousand, four hundred forty-seven".