261623330 has 16 divisors (see below), whose sum is σ = 475586424. Its totient is φ = 103612800.

The previous prime is 261623303. The next prime is 261623333. The reversal of 261623330 is 33326162.

It can be written as a sum of positive squares in 4 ways, for example, as 245454889 + 16168441 = 15667^2 + 4021^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 261623330.

It is not an unprimeable number, because it can be changed into a prime (261623333) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128507 + ... + 130526.

Almost surely, 2^261623330 is an apocalyptic number.

261623330 is a deficient number, since it is larger than the sum of its proper divisors (213963094).

261623330 is a wasteful number, since it uses less digits than its factorization.

261623330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259141.

The product of its (nonzero) digits is 3888, while the sum is 26.

The square root of 261623330 is about 16174.7744961097. The cubic root of 261623330 is about 639.5759968271.

Adding to 261623330 its reverse (33326162), we get a palindrome (294949492).

It can be divided in two parts, 26162 and 3330, that added together give a palindrome (29492).

The spelling of 261623330 in words is "two hundred sixty-one million, six hundred twenty-three thousand, three hundred thirty".