261223571 has 24 divisors (see below), whose sum is σ = 317479680. Its totient is φ = 210510576.

The previous prime is 261223549. The next prime is 261223579. The reversal of 261223571 is 175322162.

It is a happy number.

It is not a de Polignac number, because 261223571 - 2²⁶ = 194114707 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261223579) 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, 421700 + ... + 422318.

It is an arithmetic number, because the mean of its divisors is an integer number (13228320).

Almost surely, 2^261223571 is an apocalyptic number.

261223571 is a deficient number, since it is larger than the sum of its proper divisors (56256109).

261223571 is a wasteful number, since it uses less digits than its factorization.

261223571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 831 (or 812 counting only the distinct ones).

The product of its digits is 5040, while the sum is 29.

The square root of 261223571 is about 16162.4122890118. The cubic root of 261223571 is about 639.2500745740.

The spelling of 261223571 in words is "two hundred sixty-one million, two hundred twenty-three thousand, five hundred seventy-one".