648621647 has 4 divisors (see below), whose sum is σ = 648721296. Its totient is φ = 648522000.

The previous prime is 648621619. The next prime is 648621653. The reversal of 648621647 is 746126846.

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-648621647 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 648621598 and 648621607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648621947) 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, 39323 + ... + 53324.

It is an arithmetic number, because the mean of its divisors is an integer number (162180324).

Almost surely, 2^648621647 is an apocalyptic number.

648621647 is a deficient number, since it is larger than the sum of its proper divisors (99649).

648621647 is an equidigital number, since it uses as much as digits as its factorization.

648621647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99648.

The product of its digits is 387072, while the sum is 44.

The square root of 648621647 is about 25468.0514959429. The cubic root of 648621647 is about 865.6263729155.

The spelling of 648621647 in words is "six hundred forty-eight million, six hundred twenty-one thousand, six hundred forty-seven".