648311661 has 16 divisors (see below), whose sum is σ = 960897600. Its totient is φ = 432011664.

The previous prime is 648311641. The next prime is 648311663. The reversal of 648311661 is 166113846.

648311661 is a `hidden beast` number, since 6 + 483 + 116 + 61 = 666.

It is not a de Polignac number, because 648311661 - 2¹⁵ = 648278893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648311663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78895 + ... + 86723.

It is an arithmetic number, because the mean of its divisors is an integer number (60056100).

Almost surely, 2^648311661 is an apocalyptic number.

It is an amenable number.

648311661 is a deficient number, since it is larger than the sum of its proper divisors (312585939).

648311661 is a wasteful number, since it uses less digits than its factorization.

648311661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10905 (or 10899 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 648311661 is about 25461.9649870154. The cubic root of 648311661 is about 865.4884523388.

The spelling of 648311661 in words is "six hundred forty-eight million, three hundred eleven thousand, six hundred sixty-one".