261001136 has 80 divisors (see below), whose sum is σ = 591712128. Its totient is φ = 110208000.

The previous prime is 261001123. The next prime is 261001159. The reversal of 261001136 is 631100162.

It is a super-3 number, since 3×261001136³ (a number of 26 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 247811 + ... + 248861.

Almost surely, 2^261001136 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 261001136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (295856064).

261001136 is an abundant number, since it is smaller than the sum of its proper divisors (330710992).

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

261001136 is a wasteful number, since it uses less digits than its factorization.

261001136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1170 (or 1164 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 261001136 is about 16155.5295796826. The cubic root of 261001136 is about 639.0685800172.

Adding to 261001136 its reverse (631100162), we get a palindrome (892101298).

The spelling of 261001136 in words is "two hundred sixty-one million, one thousand, one hundred thirty-six".