261623427 has 16 divisors (see below), whose sum is σ = 380959488. Its totient is φ = 158729760.

The previous prime is 261623389. The next prime is 261623441. The reversal of 261623427 is 724326162.

It is not a de Polignac number, because 261623427 - 2⁸ = 261623171 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261623447) 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 15 ways as a sum of consecutive naturals, for example, 44473 + ... + 50010.

It is an arithmetic number, because the mean of its divisors is an integer number (23809968).

Almost surely, 2^261623427 is an apocalyptic number.

261623427 is a deficient number, since it is larger than the sum of its proper divisors (119336061).

261623427 is a wasteful number, since it uses less digits than its factorization.

261623427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94570.

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

The square root of 261623427 is about 16174.7774946056. Note that the first 3 decimals coincide. The cubic root of 261623427 is about 639.5760758706.

Adding to 261623427 its reverse (724326162), we get a palindrome (985949589).

The spelling of 261623427 in words is "two hundred sixty-one million, six hundred twenty-three thousand, four hundred twenty-seven".