261244016 has 40 divisors (see below), whose sum is σ = 555024000. Its totient is φ = 118134720.

The previous prime is 261244007. The next prime is 261244019. The reversal of 261244016 is 610442162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261244019) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31295 + ... + 38753.

It is an arithmetic number, because the mean of its divisors is an integer number (13875600).

Almost surely, 2^261244016 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 261244016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277512000).

261244016 is an abundant number, since it is smaller than the sum of its proper divisors (293779984).

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

261244016 is a wasteful number, since it uses less digits than its factorization.

261244016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7677 (or 7671 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 261244016 is about 16163.0447626677. The cubic root of 261244016 is about 639.2667513830.

Adding to 261244016 its reverse (610442162), we get a palindrome (871686178).

The spelling of 261244016 in words is "two hundred sixty-one million, two hundred forty-four thousand, sixteen".