261623016 has 24 divisors (see below), whose sum is σ = 708562530. Its totient is φ = 87207648.

The previous prime is 261622993. The next prime is 261623017. The reversal of 261623016 is 610326162.

261623016 is a `hidden beast` number, since 2 + 616 + 2 + 30 + 16 = 666.

It can be written as a sum of positive squares in only one way, i.e., 259532100 + 2090916 = 16110^2 + 1446^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (261623017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1816755 + ... + 1816898.

Almost surely, 2^261623016 is an apocalyptic number.

It is an amenable number.

261623016 is an abundant number, since it is smaller than the sum of its proper divisors (446939514).

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

261623016 is a wasteful number, since it uses less digits than its factorization.

261623016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3633665 (or 3633658 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 261623016 is about 16174.7647896345. The cubic root of 261623016 is about 639.5757409542.

Adding to 261623016 its reverse (610326162), we get a palindrome (871949178).

The spelling of 261623016 in words is "two hundred sixty-one million, six hundred twenty-three thousand, sixteen".