261039820 has 12 divisors (see below), whose sum is σ = 548183664. Its totient is φ = 104415920.

The previous prime is 261039797. The next prime is 261039827. The reversal of 261039820 is 28930162.

261039820 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 (261039827) 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, 6525976 + ... + 6526015.

It is an arithmetic number, because the mean of its divisors is an integer number (45681972).

Almost surely, 2^261039820 is an apocalyptic number.

261039820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261039820 is an abundant number, since it is smaller than the sum of its proper divisors (287143844).

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

261039820 is a wasteful number, since it uses less digits than its factorization.

261039820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13052000 (or 13051998 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 261039820 is about 16156.7267724623. The cubic root of 261039820 is about 639.1001514094.

Adding to 261039820 its reverse (28930162), we get a palindrome (289969982).

The spelling of 261039820 in words is "two hundred sixty-one million, thirty-nine thousand, eight hundred twenty".