261523573 has 4 divisors (see below), whose sum is σ = 261776320. Its totient is φ = 261270828.

The previous prime is 261523567. The next prime is 261523589. The reversal of 261523573 is 375325162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261523573 - 2⁵ = 261523541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261523673) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124815 + ... + 126892.

It is an arithmetic number, because the mean of its divisors is an integer number (65444080).

Almost surely, 2^261523573 is an apocalyptic number.

It is an amenable number.

261523573 is a deficient number, since it is larger than the sum of its proper divisors (252747).

261523573 is a wasteful number, since it uses less digits than its factorization.

261523573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252746.

The product of its digits is 37800, while the sum is 34.

The square root of 261523573 is about 16171.6904805898. The cubic root of 261523573 is about 639.4946963640.

The spelling of 261523573 in words is "two hundred sixty-one million, five hundred twenty-three thousand, five hundred seventy-three".