261188400 has 240 divisors, whose sum is σ = 934368768. Its totient is φ = 61824000.

The previous prime is 261188393. The next prime is 261188419. The reversal of 261188400 is 4881162.

261188400 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 (240).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 620190 + ... + 620610.

Almost surely, 2^261188400 is an apocalyptic number.

261188400 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 261188400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (467184384).

261188400 is an abundant number, since it is smaller than the sum of its proper divisors (673180368).

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

261188400 is a wasteful number, since it uses less digits than its factorization.

261188400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500 (or 489 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 261188400 is about 16161.3242031710. The cubic root of 261188400 is about 639.2213838585.

The spelling of 261188400 in words is "two hundred sixty-one million, one hundred eighty-eight thousand, four hundred".