65375780521 has 4 divisors (see below), whose sum is σ = 65986769232. Its totient is φ = 64764791812.

The previous prime is 65375780513. The next prime is 65375780531. The reversal of 65375780521 is 12508757356.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 65375780521 - 2³ = 65375780513 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65375780531) 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, 305494195 + ... + 305494408.

It is an arithmetic number, because the mean of its divisors is an integer number (16496692308).

Almost surely, 2^65375780521 is an apocalyptic number.

It is an amenable number.

65375780521 is a deficient number, since it is larger than the sum of its proper divisors (610988711).

65375780521 is a wasteful number, since it uses less digits than its factorization.

65375780521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610988710.

The product of its (nonzero) digits is 1764000, while the sum is 49.

The spelling of 65375780521 in words is "sixty-five billion, three hundred seventy-five million, seven hundred eighty thousand, five hundred twenty-one".