688782949 has 2 divisors, whose sum is σ = 688782950. Its totient is φ = 688782948.

The previous prime is 688782917. The next prime is 688782953. The reversal of 688782949 is 949287886.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 449864100 + 238918849 = 21210^2 + 15457^2 .

It is a cyclic number.

It is not a de Polignac number, because 688782949 - 2⁵ = 688782917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688782749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344391474 + 344391475.

It is an arithmetic number, because the mean of its divisors is an integer number (344391475).

Almost surely, 2^688782949 is an apocalyptic number.

It is an amenable number.

688782949 is a deficient number, since it is larger than the sum of its proper divisors (1).

688782949 is an equidigital number, since it uses as much as digits as its factorization.

688782949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13934592, while the sum is 61.

The square root of 688782949 is about 26244.6746788753. The cubic root of 688782949 is about 883.1357435192.

The spelling of 688782949 in words is "six hundred eighty-eight million, seven hundred eighty-two thousand, nine hundred forty-nine".