261540064 has 12 divisors (see below), whose sum is σ = 514907064. Its totient is φ = 130770016.

The previous prime is 261540049. The next prime is 261540077. The reversal of 261540064 is 460045162.

261540064 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4086532 + ... + 4086595.

It is an arithmetic number, because the mean of its divisors is an integer number (42908922).

Almost surely, 2^261540064 is an apocalyptic number.

It is an amenable number.

261540064 is a deficient number, since it is larger than the sum of its proper divisors (253367000).

261540064 is an equidigital number, since it uses as much as digits as its factorization.

261540064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8173137 (or 8173129 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 261540064 is about 16172.2003450365. The cubic root of 261540064 is about 639.5081377085.

The spelling of 261540064 in words is "two hundred sixty-one million, five hundred forty thousand, sixty-four".