261312120 has 48 divisors (see below), whose sum is σ = 849265560. Its totient is φ = 69683136.

The previous prime is 261312089. The next prime is 261312169. The reversal of 261312120 is 21213162.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 261312093 and 261312102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 362574 + ... + 363293.

Almost surely, 2^261312120 is an apocalyptic number.

261312120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261312120 is an abundant number, since it is smaller than the sum of its proper divisors (587953440).

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

261312120 is a wasteful number, since it uses less digits than its factorization.

261312120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725884 (or 725877 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 261312120 is about 16165.1514066525. The cubic root of 261312120 is about 639.3222969490.

Adding to 261312120 its reverse (21213162), we get a palindrome (282525282).

The spelling of 261312120 in words is "two hundred sixty-one million, three hundred twelve thousand, one hundred twenty".