261186380 has 48 divisors (see below), whose sum is σ = 675071040. Its totient is φ = 82660608.

The previous prime is 261186337. The next prime is 261186389. The reversal of 261186380 is 83681162.

261186380 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 261186380.

It is not an unprimeable number, because it can be changed into a prime (261186389) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69935 + ... + 73574.

It is an arithmetic number, because the mean of its divisors is an integer number (14063980).

Almost surely, 2^261186380 is an apocalyptic number.

261186380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261186380 is an abundant number, since it is smaller than the sum of its proper divisors (413884660).

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

261186380 is a wasteful number, since it uses less digits than its factorization.

261186380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143538 (or 143536 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 261186380 is about 16161.2617081712. The cubic root of 261186380 is about 639.2197359669.

The spelling of 261186380 in words is "two hundred sixty-one million, one hundred eighty-six thousand, three hundred eighty".