4640681861 has 2 divisors, whose sum is σ = 4640681862. Its totient is φ = 4640681860.

The previous prime is 4640681849. The next prime is 4640681869. The reversal of 4640681861 is 1681860464.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2339656900 + 2301024961 = 48370^2 + 47969^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4640681861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4640681869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2320340930 + 2320340931.

It is an arithmetic number, because the mean of its divisors is an integer number (2320340931).

Almost surely, 2^4640681861 is an apocalyptic number.

It is an amenable number.

4640681861 is a deficient number, since it is larger than the sum of its proper divisors (1).

4640681861 is an equidigital number, since it uses as much as digits as its factorization.

4640681861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 221184, while the sum is 44.

The square root of 4640681861 is about 68122.5503119195. The cubic root of 4640681861 is about 1667.9918804369.

The spelling of 4640681861 in words is "four billion, six hundred forty million, six hundred eighty-one thousand, eight hundred sixty-one".