7816487989 has 2 divisors, whose sum is σ = 7816487990. Its totient is φ = 7816487988.

The previous prime is 7816487983. The next prime is 7816488023. The reversal of 7816487989 is 9897846187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5210385489 + 2606102500 = 72183^2 + 51050^2 .

It is a cyclic number.

It is not a de Polignac number, because 7816487989 - 2³ = 7816487981 is a prime.

It is a super-2 number, since 2×7816487989² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7816487981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3908243994 + 3908243995.

It is an arithmetic number, because the mean of its divisors is an integer number (3908243995).

Almost surely, 2^7816487989 is an apocalyptic number.

It is an amenable number.

7816487989 is a deficient number, since it is larger than the sum of its proper divisors (1).

7816487989 is an equidigital number, since it uses as much as digits as its factorization.

7816487989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48771072, while the sum is 67.

The square root of 7816487989 is about 88410.9042426329. The cubic root of 7816487989 is about 1984.5888862174.

The spelling of 7816487989 in words is "seven billion, eight hundred sixteen million, four hundred eighty-seven thousand, nine hundred eighty-nine".