1648657261 has 2 divisors, whose sum is σ = 1648657262. Its totient is φ = 1648657260.

The previous prime is 1648657253. The next prime is 1648657277. The reversal of 1648657261 is 1627568461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1057875625 + 590781636 = 32525^2 + 24306^2 .

It is a cyclic number.

It is not a de Polignac number, because 1648657261 - 2³ = 1648657253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1648657291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824328630 + 824328631.

It is an arithmetic number, because the mean of its divisors is an integer number (824328631).

Almost surely, 2^1648657261 is an apocalyptic number.

It is an amenable number.

1648657261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1648657261 is an equidigital number, since it uses as much as digits as its factorization.

1648657261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 46.

The square root of 1648657261 is about 40603.6606847215. The cubic root of 1648657261 is about 1181.3451243497.

The spelling of 1648657261 in words is "one billion, six hundred forty-eight million, six hundred fifty-seven thousand, two hundred sixty-one".