261305100 has 432 divisors, whose sum is σ = 1029100800. Its totient is φ = 54120960.

The previous prime is 261305089. The next prime is 261305111. The reversal of 261305100 is 1503162.

261305100 is a `hidden beast` number, since 2 + 613 + 0 + 51 + 0 + 0 = 666.

261305100 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (261305089) and next prime (261305111).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 4428871 + ... + 4428929.

Almost surely, 2^261305100 is an apocalyptic number.

261305100 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 261305100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (514550400).

261305100 is an abundant number, since it is smaller than the sum of its proper divisors (767795700).

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

261305100 is a wasteful number, since it uses less digits than its factorization.

261305100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 261305100 is about 16164.9342714408. The cubic root of 261305100 is about 639.3165718890.

Adding to 261305100 its reverse (1503162), we get a palindrome (262808262).

The spelling of 261305100 in words is "two hundred sixty-one million, three hundred five thousand, one hundred".