261151920 has 120 divisors (see below), whose sum is σ = 900830736. Its totient is φ = 67751424.

The previous prime is 261151907. The next prime is 261151939. The reversal of 261151920 is 29151162.

261151920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (120).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21739 + ... + 31541.

Almost surely, 2^261151920 is an apocalyptic number.

261151920 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 261151920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (450415368).

261151920 is an abundant number, since it is smaller than the sum of its proper divisors (639678816).

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

261151920 is a wasteful number, since it uses less digits than its factorization.

261151920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9859 (or 9850 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 261151920 is about 16160.1955433714. The cubic root of 261151920 is about 639.1916226059.

The spelling of 261151920 in words is "two hundred sixty-one million, one hundred fifty-one thousand, nine hundred twenty".