261442401 has 24 divisors (see below), whose sum is σ = 389475072. Its totient is φ = 155839200.

The previous prime is 261442399. The next prime is 261442417. The reversal of 261442401 is 104244162.

It is a happy number.

It is not a de Polignac number, because 261442401 - 2¹ = 261442399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261442421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16240 + ... + 28046.

It is an arithmetic number, because the mean of its divisors is an integer number (16228128).

Almost surely, 2^261442401 is an apocalyptic number.

It is an amenable number.

261442401 is a deficient number, since it is larger than the sum of its proper divisors (128032671).

261442401 is a wasteful number, since it uses less digits than its factorization.

261442401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11893 (or 11882 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 261442401 is about 16169.1805914833. The cubic root of 261442401 is about 639.4285271408.

Adding to 261442401 its reverse (104244162), we get a palindrome (365686563).

The spelling of 261442401 in words is "two hundred sixty-one million, four hundred forty-two thousand, four hundred one".