261164790 has 128 divisors (see below), whose sum is σ = 719418240. Its totient is φ = 67392000.

The previous prime is 261164789. The next prime is 261164791. The reversal of 261164790 is 97461162.

261164790 is a `hidden beast` number, since 2 + 6 + 1 + 1 + 647 + 9 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (261164789) and next prime (261164791).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261164791) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1663392 + ... + 1663548.

It is an arithmetic number, because the mean of its divisors is an integer number (5620455).

Almost surely, 2^261164790 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261164790, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (359709120).

261164790 is an abundant number, since it is smaller than the sum of its proper divisors (458253450).

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

261164790 is a wasteful number, since it uses less digits than its factorization.

261164790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335 (or 329 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 261164790 is about 16160.5937390926. The cubic root of 261164790 is about 639.2021225747.

The spelling of 261164790 in words is "two hundred sixty-one million, one hundred sixty-four thousand, seven hundred ninety".