261399672 has 48 divisors (see below), whose sum is σ = 727098840. Its totient is φ = 84777408.

The previous prime is 261399659. The next prime is 261399673. The reversal of 261399672 is 276993162.

It is a happy number.

261399672 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261399673) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 46398 + ... + 51725.

Almost surely, 2^261399672 is an apocalyptic number.

It is an amenable number.

261399672 is an abundant number, since it is smaller than the sum of its proper divisors (465699168).

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

261399672 is a wasteful number, since it uses less digits than its factorization.

261399672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98172 (or 98165 counting only the distinct ones).

The product of its digits is 244944, while the sum is 45.

The square root of 261399672 is about 16167.8592274921. The cubic root of 261399672 is about 639.3936901110.

The spelling of 261399672 in words is "two hundred sixty-one million, three hundred ninety-nine thousand, six hundred seventy-two".