649777521577 has 2 divisors, whose sum is σ = 649777521578. Its totient is φ = 649777521576.

The previous prime is 649777521571. The next prime is 649777521661. The reversal of 649777521577 is 775125777946.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 489249887296 + 160527634281 = 699464^2 + 400659^2 .

It is a cyclic number.

It is not a de Polignac number, because 649777521577 - 2¹⁵ = 649777488809 is a prime.

It is not a weakly prime, because it can be changed into another prime (649777521571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324888760788 + 324888760789.

It is an arithmetic number, because the mean of its divisors is an integer number (324888760789).

Almost surely, 2^649777521577 is an apocalyptic number.

It is an amenable number.

649777521577 is a deficient number, since it is larger than the sum of its proper divisors (1).

649777521577 is an equidigital number, since it uses as much as digits as its factorization.

649777521577 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181515600, while the sum is 67.

The spelling of 649777521577 in words is "six hundred forty-nine billion, seven hundred seventy-seven million, five hundred twenty-one thousand, five hundred seventy-seven".