690688123 has 2 divisors, whose sum is σ = 690688124. Its totient is φ = 690688122.

The previous prime is 690688111. The next prime is 690688211. The reversal of 690688123 is 321886096.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 690688123 - 2¹³ = 690679931 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 690688123.

It is not a weakly prime, because it can be changed into another prime (690688423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345344061 + 345344062.

It is an arithmetic number, because the mean of its divisors is an integer number (345344062).

Almost surely, 2^690688123 is an apocalyptic number.

690688123 is a deficient number, since it is larger than the sum of its proper divisors (1).

690688123 is an equidigital number, since it uses as much as digits as its factorization.

690688123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 690688123 is about 26280.9460065653. The cubic root of 690688123 is about 883.9492452416.

The spelling of 690688123 in words is "six hundred ninety million, six hundred eighty-eight thousand, one hundred twenty-three".