261123264 has 140 divisors (see below), whose sum is σ = 819860184. Its totient is φ = 81893376.

The previous prime is 261123257. The next prime is 261123277. The reversal of 261123264 is 462321162.

261123264 is a `hidden beast` number, since 2 + 611 + 23 + 26 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 86647 + ... + 89609.

Almost surely, 2^261123264 is an apocalyptic number.

261123264 is a gapful number since it is divisible by the number (24) 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 261123264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (409930092).

261123264 is an abundant number, since it is smaller than the sum of its proper divisors (558736920).

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

261123264 is a wasteful number, since it uses less digits than its factorization.

261123264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3004 (or 2985 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 261123264 is about 16159.3088961131. The cubic root of 261123264 is about 639.1682424151.

The spelling of 261123264 in words is "two hundred sixty-one million, one hundred twenty-three thousand, two hundred sixty-four".