501640549 has 2 divisors, whose sum is σ = 501640550. Its totient is φ = 501640548.

The previous prime is 501640547. The next prime is 501640553. The reversal of 501640549 is 945046105.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 477728449 + 23912100 = 21857^2 + 4890^2 .

It is a cyclic number.

It is not a de Polignac number, because 501640549 - 2¹ = 501640547 is a prime.

Together with 501640547, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (501640547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 250820274 + 250820275.

It is an arithmetic number, because the mean of its divisors is an integer number (250820275).

Almost surely, 2^501640549 is an apocalyptic number.

It is an amenable number.

501640549 is a deficient number, since it is larger than the sum of its proper divisors (1).

501640549 is an equidigital number, since it uses as much as digits as its factorization.

501640549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 501640549 is about 22397.3335243283. Note that the first 3 decimals coincide. The cubic root of 501640549 is about 794.5676480398.

The spelling of 501640549 in words is "five hundred one million, six hundred forty thousand, five hundred forty-nine".