689812049 has 2 divisors, whose sum is σ = 689812050. Its totient is φ = 689812048.

The previous prime is 689812027. The next prime is 689812061. The reversal of 689812049 is 940218986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 408646225 + 281165824 = 20215^2 + 16768^2 .

It is a cyclic number.

It is not a de Polignac number, because 689812049 - 2¹² = 689807953 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 689811994 and 689812012.

It is not a weakly prime, because it can be changed into another prime (689872049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344906024 + 344906025.

It is an arithmetic number, because the mean of its divisors is an integer number (344906025).

Almost surely, 2^689812049 is an apocalyptic number.

It is an amenable number.

689812049 is a deficient number, since it is larger than the sum of its proper divisors (1).

689812049 is an equidigital number, since it uses as much as digits as its factorization.

689812049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 689812049 is about 26264.2732433243. The cubic root of 689812049 is about 883.5753511609.

The spelling of 689812049 in words is "six hundred eighty-nine million, eight hundred twelve thousand, forty-nine".