261572471 has 4 divisors (see below), whose sum is σ = 261658992. Its totient is φ = 261485952.

The previous prime is 261572461. The next prime is 261572477. The reversal of 261572471 is 174275162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 174275162 = 2 ⋅87137581.

It is a cyclic number.

It is not a de Polignac number, because 261572471 - 2²² = 257378167 is a prime.

It is a super-3 number, since 3×261572471³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261572477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38555 + ... + 44828.

It is an arithmetic number, because the mean of its divisors is an integer number (65414748).

Almost surely, 2^261572471 is an apocalyptic number.

261572471 is a deficient number, since it is larger than the sum of its proper divisors (86521).

261572471 is an equidigital number, since it uses as much as digits as its factorization.

261572471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86520.

The product of its digits is 23520, while the sum is 35.

The square root of 261572471 is about 16173.2022494001. The cubic root of 261572471 is about 639.5345500855.

The spelling of 261572471 in words is "two hundred sixty-one million, five hundred seventy-two thousand, four hundred seventy-one".