521640011 has 4 divisors (see below), whose sum is σ = 521830632. Its totient is φ = 521449392.

The previous prime is 521639999. The next prime is 521640013. The reversal of 521640011 is 110046125.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521640011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521640013) 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, 91145 + ... + 96698.

It is an arithmetic number, because the mean of its divisors is an integer number (130457658).

Almost surely, 2^521640011 is an apocalyptic number.

521640011 is a deficient number, since it is larger than the sum of its proper divisors (190621).

521640011 is a wasteful number, since it uses less digits than its factorization.

521640011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190620.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 521640011 is about 22839.4398136206. The cubic root of 521640011 is about 804.9896535584.

Adding to 521640011 its reverse (110046125), we get a palindrome (631686136).

The spelling of 521640011 in words is "five hundred twenty-one million, six hundred forty thousand, eleven".