261797980 has 24 divisors (see below), whose sum is σ = 550079712. Its totient is φ = 104661312.

The previous prime is 261797947. The next prime is 261797989. The reversal of 261797980 is 89797162.

It is a happy number.

261797980 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261797989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70449 + ... + 74071.

It is an arithmetic number, because the mean of its divisors is an integer number (22919988).

Almost surely, 2^261797980 is an apocalyptic number.

261797980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261797980 is an abundant number, since it is smaller than the sum of its proper divisors (288281732).

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

261797980 is a wasteful number, since it uses less digits than its factorization.

261797980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7245 (or 7243 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 49.

The square root of 261797980 is about 16180.1724341862. The cubic root of 261797980 is about 639.7182842154.

The spelling of 261797980 in words is "two hundred sixty-one million, seven hundred ninety-seven thousand, nine hundred eighty".