261626816 has 56 divisors (see below), whose sum is σ = 578486016. Its totient is φ = 116376320.

The previous prime is 261626809. The next prime is 261626831. The reversal of 261626816 is 618626162.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 261626816.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29135 + ... + 37041.

Almost surely, 2^261626816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261626816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (289243008).

261626816 is an abundant number, since it is smaller than the sum of its proper divisors (316859200).

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

261626816 is a wasteful number, since it uses less digits than its factorization.

261626816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7977 (or 7967 counting only the distinct ones).

The product of its digits is 41472, while the sum is 38.

The square root of 261626816 is about 16174.8822561402. The cubic root of 261626816 is about 639.5788374912.

The spelling of 261626816 in words is "two hundred sixty-one million, six hundred twenty-six thousand, eight hundred sixteen".