64185077261 has 4 divisors (see below), whose sum is σ = 64209236892. Its totient is φ = 64160917632.

The previous prime is 64185077251. The next prime is 64185077263. The reversal of 64185077261 is 16277058146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16277058146 = 2 ⋅8138529073.

It can be written as a sum of positive squares in 2 ways, for example, as 20658600361 + 43526476900 = 143731^2 + 208630^2 .

It is a cyclic number.

It is not a de Polignac number, because 64185077261 - 2⁶ = 64185077197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64185077263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12075830 + ... + 12081143.

It is an arithmetic number, because the mean of its divisors is an integer number (16052309223).

Almost surely, 2^64185077261 is an apocalyptic number.

It is an amenable number.

64185077261 is a deficient number, since it is larger than the sum of its proper divisors (24159631).

64185077261 is a wasteful number, since it uses less digits than its factorization.

64185077261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24159630.

The product of its (nonzero) digits is 564480, while the sum is 47.

The spelling of 64185077261 in words is "sixty-four billion, one hundred eighty-five million, seventy-seven thousand, two hundred sixty-one".