261244405 has 8 divisors (see below), whose sum is σ = 314244000. Its totient is φ = 208495056.

The previous prime is 261244397. The next prime is 261244411. The reversal of 261244405 is 504442162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261244405 - 2³ = 261244397 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60255 + ... + 64444.

It is an arithmetic number, because the mean of its divisors is an integer number (39280500).

Almost surely, 2^261244405 is an apocalyptic number.

It is an amenable number.

261244405 is a deficient number, since it is larger than the sum of its proper divisors (52999595).

261244405 is a wasteful number, since it uses less digits than its factorization.

261244405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125123.

The product of its (nonzero) digits is 7680, while the sum is 28.

The square root of 261244405 is about 16163.0567962870. The cubic root of 261244405 is about 639.2670686785.

Adding to 261244405 its reverse (504442162), we get a palindrome (765686567).

The spelling of 261244405 in words is "two hundred sixty-one million, two hundred forty-four thousand, four hundred five".