261171020 has 24 divisors (see below), whose sum is σ = 598319568. Its totient is φ = 94971200.

The previous prime is 261171011. The next prime is 261171041. The reversal of 261171020 is 20171162.

261171020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 261170983 and 261171001.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 593351 + ... + 593790.

It is an arithmetic number, because the mean of its divisors is an integer number (24929982).

Almost surely, 2^261171020 is an apocalyptic number.

261171020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261171020 is an abundant number, since it is smaller than the sum of its proper divisors (337148548).

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

261171020 is a wasteful number, since it uses less digits than its factorization.

261171020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1187161 (or 1187159 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 261171020 is about 16160.7864907621. The cubic root of 261171020 is about 639.2072051863.

The spelling of 261171020 in words is "two hundred sixty-one million, one hundred seventy-one thousand, twenty".