261731406 has 8 divisors (see below), whose sum is σ = 523462824. Its totient is φ = 87243800.

The previous prime is 261731399. The next prime is 261731417. The reversal of 261731406 is 604137162.

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

261731406 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21810945 + ... + 21810956.

It is an arithmetic number, because the mean of its divisors is an integer number (65432853).

Almost surely, 2^261731406 is an apocalyptic number.

261731406 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261731406 is a wasteful number, since it uses less digits than its factorization.

261731406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43621906.

The product of its (nonzero) digits is 6048, while the sum is 30.

The square root of 261731406 is about 16178.1150323516. The cubic root of 261731406 is about 639.6640538306.

Adding to 261731406 its reverse (604137162), we get a palindrome (865868568).

The spelling of 261731406 in words is "two hundred sixty-one million, seven hundred thirty-one thousand, four hundred six".