261880000 has 70 divisors (see below), whose sum is σ = 649476476. Its totient is φ = 104736000.

The previous prime is 261879973. The next prime is 261880007. The reversal of 261880000 is 88162.

It is a super-2 number, since 2×261880000² = 137162268800000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (261880007) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 36727 + ... + 43273.

Almost surely, 2^261880000 is an apocalyptic number.

261880000 is a gapful number since it is divisible by the number (20) 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 261880000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324738238).

261880000 is an abundant number, since it is smaller than the sum of its proper divisors (387596476).

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

261880000 is an frugal number, since it uses more digits than its factorization.

261880000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6579 (or 6554 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 261880000 is about 16182.7068193180. The cubic root of 261880000 is about 639.7850840880.

The spelling of 261880000 in words is "two hundred sixty-one million, eight hundred eighty thousand".