648663434521 has 2 divisors, whose sum is σ = 648663434522. Its totient is φ = 648663434520.

The previous prime is 648663434479. The next prime is 648663434563. The reversal of 648663434521 is 125434366846.

It is a balanced prime because it is at equal distance from previous prime (648663434479) and next prime (648663434563).

It can be written as a sum of positive squares in only one way, i.e., 352199519296 + 296463915225 = 593464^2 + 544485^2 .

It is a cyclic number.

It is not a de Polignac number, because 648663434521 - 2³³ = 640073499929 is a prime.

It is not a weakly prime, because it can be changed into another prime (648663434021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324331717260 + 324331717261.

It is an arithmetic number, because the mean of its divisors is an integer number (324331717261).

Almost surely, 2^648663434521 is an apocalyptic number.

It is an amenable number.

648663434521 is a deficient number, since it is larger than the sum of its proper divisors (1).

648663434521 is an equidigital number, since it uses as much as digits as its factorization.

648663434521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9953280, while the sum is 52.

The spelling of 648663434521 in words is "six hundred forty-eight billion, six hundred sixty-three million, four hundred thirty-four thousand, five hundred twenty-one".