261161274 has 64 divisors (see below), whose sum is σ = 608560128. Its totient is φ = 73920000.

The previous prime is 261161273. The next prime is 261161279. The reversal of 261161274 is 472161162.

It is a super-2 number, since 2×261161274² = 136410422074606152, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261161273) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 63274 + ... + 67274.

It is an arithmetic number, because the mean of its divisors is an integer number (9508752).

Almost surely, 2^261161274 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261161274, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (304280064).

261161274 is an abundant number, since it is smaller than the sum of its proper divisors (347398854).

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

261161274 is a wasteful number, since it uses less digits than its factorization.

261161274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4083.

The product of its digits is 4032, while the sum is 30.

The square root of 261161274 is about 16160.4849555946. The cubic root of 261161274 is about 639.1992540860.

The spelling of 261161274 in words is "two hundred sixty-one million, one hundred sixty-one thousand, two hundred seventy-four".