247806989 has 2 divisors, whose sum is σ = 247806990. Its totient is φ = 247806988.

The previous prime is 247806929. The next prime is 247806997. The reversal of 247806989 is 989608742.

247806989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 145998889 + 101808100 = 12083^2 + 10090^2 .

It is a cyclic number.

It is not a de Polignac number, because 247806989 - 2⁸ = 247806733 is a prime.

It is a super-2 number, since 2×247806989² = 122816607594492242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 247806989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247806929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123903494 + 123903495.

It is an arithmetic number, because the mean of its divisors is an integer number (123903495).

Almost surely, 2^247806989 is an apocalyptic number.

It is an amenable number.

247806989 is a deficient number, since it is larger than the sum of its proper divisors (1).

247806989 is an equidigital number, since it uses as much as digits as its factorization.

247806989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1741824, while the sum is 53.

The square root of 247806989 is about 15741.8864498509. The cubic root of 247806989 is about 628.1130986549.

The spelling of 247806989 in words is "two hundred forty-seven million, eight hundred six thousand, nine hundred eighty-nine".