64847547581 has 2 divisors, whose sum is σ = 64847547582. Its totient is φ = 64847547580.

The previous prime is 64847547553. The next prime is 64847547641. The reversal of 64847547581 is 18574574846.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54491432356 + 10356115225 = 233434^2 + 101765^2 .

It is a cyclic number.

It is not a de Polignac number, because 64847547581 - 2⁶ = 64847547517 is a prime.

It is a super-2 number, since 2×64847547581² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64847547581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64847547521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32423773790 + 32423773791.

It is an arithmetic number, because the mean of its divisors is an integer number (32423773791).

Almost surely, 2^64847547581 is an apocalyptic number.

It is an amenable number.

64847547581 is a deficient number, since it is larger than the sum of its proper divisors (1).

64847547581 is an equidigital number, since it uses as much as digits as its factorization.

64847547581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30105600, while the sum is 59.

The spelling of 64847547581 in words is "sixty-four billion, eight hundred forty-seven million, five hundred forty-seven thousand, five hundred eighty-one".