261319820 has 12 divisors (see below), whose sum is σ = 548771664. Its totient is φ = 104527920.

The previous prime is 261319769. The next prime is 261319823. The reversal of 261319820 is 28913162.

261319820 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (261319823) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6532976 + ... + 6533015.

It is an arithmetic number, because the mean of its divisors is an integer number (45730972).

Almost surely, 2^261319820 is an apocalyptic number.

261319820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261319820 is an abundant number, since it is smaller than the sum of its proper divisors (287451844).

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

261319820 is a wasteful number, since it uses less digits than its factorization.

261319820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13066000 (or 13065998 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 261319820 is about 16165.3895715507. The cubic root of 261319820 is about 639.3285764553.

The spelling of 261319820 in words is "two hundred sixty-one million, three hundred nineteen thousand, eight hundred twenty".