261861450 has 48 divisors (see below), whose sum is σ = 653234976. Its totient is φ = 69419200.

The previous prime is 261861437. The next prime is 261861451. The reversal of 261861450 is 54168162.

It is a super-2 number, since 2×261861450² = 137142837992205000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261861451) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20905 + ... + 30995.

It is an arithmetic number, because the mean of its divisors is an integer number (13609062).

Almost surely, 2^261861450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261861450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326617488).

261861450 is an abundant number, since it is smaller than the sum of its proper divisors (391373526).

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

261861450 is a wasteful number, since it uses less digits than its factorization.

261861450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10279 (or 10274 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 261861450 is about 16182.1336664854. The cubic root of 261861450 is about 639.7699775589.

The spelling of 261861450 in words is "two hundred sixty-one million, eight hundred sixty-one thousand, four hundred fifty".