261071616 has 144 divisors (see below), whose sum is σ = 760040960. Its totient is φ = 79073280.

The previous prime is 261071611. The next prime is 261071633. The reversal of 261071616 is 616170162.

It is not an unprimeable number, because it can be changed into a prime (261071611) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 788571 + ... + 788901.

Almost surely, 2^261071616 is an apocalyptic number.

261071616 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261071616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (380020480).

261071616 is an abundant number, since it is smaller than the sum of its proper divisors (498969344).

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

261071616 is a wasteful number, since it uses less digits than its factorization.

261071616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 442 (or 428 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 261071616 is about 16157.7107289368. The cubic root of 261071616 is about 639.1260989237.

The spelling of 261071616 in words is "two hundred sixty-one million, seventy-one thousand, six hundred sixteen".