261864450 has 36 divisors (see below), whose sum is σ = 703543698. Its totient is φ = 69830400.

The previous prime is 261864439. The next prime is 261864451. The reversal of 261864450 is 54468162.

261864450 is a `hidden beast` number, since 2 + 6 + 1 + 8 + 644 + 5 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 229613409 + 32251041 = 15153^2 + 5679^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (261864451) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 290511 + ... + 291410.

Almost surely, 2^261864450 is an apocalyptic number.

261864450 is an abundant number, since it is smaller than the sum of its proper divisors (441679248).

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

261864450 is a wasteful number, since it uses less digits than its factorization.

261864450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 581939 (or 581931 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 261864450 is about 16182.2263610419. The cubic root of 261864450 is about 639.7724207117.

The spelling of 261864450 in words is "two hundred sixty-one million, eight hundred sixty-four thousand, four hundred fifty".