4999999861 has 2 divisors, whose sum is σ = 4999999862. Its totient is φ = 4999999860.

The previous prime is 4999999859. The next prime is 4999999867. The reversal of 4999999861 is 1689999994.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4560300900 + 439698961 = 67530^2 + 20969^2 .

It is a cyclic number.

It is not a de Polignac number, because 4999999861 - 2¹ = 4999999859 is a prime.

It is a super-2 number, since 2×4999999861² = 49999997220000038642, which contains 22 as substring.

Together with 4999999859, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4999999867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2499999930 + 2499999931.

It is an arithmetic number, because the mean of its divisors is an integer number (2499999931).

Almost surely, 2^4999999861 is an apocalyptic number.

It is an amenable number.

4999999861 is a deficient number, since it is larger than the sum of its proper divisors (1).

4999999861 is an equidigital number, since it uses as much as digits as its factorization.

4999999861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 102036672, while the sum is 73.

The square root of 4999999861 is about 70710.6771357763. The cubic root of 4999999861 is about 1709.9759308309.

The spelling of 4999999861 in words is "four billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred sixty-one".