261664039 has 16 divisors (see below), whose sum is σ = 326592000. Its totient is φ = 204109920.

The previous prime is 261664019. The next prime is 261664049. The reversal of 261664039 is 930466162.

It is a happy number.

It is not a de Polignac number, because 261664039 - 2⁷ = 261663911 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261663989 and 261664007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261664019) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13789 + ... + 26710.

It is an arithmetic number, because the mean of its divisors is an integer number (20412000).

Almost surely, 2^261664039 is an apocalyptic number.

261664039 is a deficient number, since it is larger than the sum of its proper divisors (64927961).

261664039 is a wasteful number, since it uses less digits than its factorization.

261664039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40590.

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 261664039 is about 16176.0328572861. The cubic root of 261664039 is about 639.6091681157.

The spelling of 261664039 in words is "two hundred sixty-one million, six hundred sixty-four thousand, thirty-nine".