261918819162 has 384 divisors, whose sum is σ = 805030410240. Its totient is φ = 61259328000.

The previous prime is 261918819157. The next prime is 261918819257.

261918819162 is a `hidden beast` number, since 2 + 619 + 1 + 8 + 8 + 1 + 9 + 16 + 2 = 666.

261918819162 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 261918819099 and 261918819108.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 28806237 + ... + 28815327.

It is an arithmetic number, because the mean of its divisors is an integer number (2096433360).

Almost surely, 2^261918819162 is an apocalyptic number.

261918819162 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 261918819162, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (402515205120).

261918819162 is an abundant number, since it is smaller than the sum of its proper divisors (543111591078).

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

261918819162 is a wasteful number, since it uses less digits than its factorization.

261918819162 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9187 (or 9168 counting only the distinct ones).

The product of its digits is 746496, while the sum is 54.

The spelling of 261918819162 in words is "two hundred sixty-one billion, nine hundred eighteen million, eight hundred nineteen thousand, one hundred sixty-two".