690916649 has 2 divisors, whose sum is σ = 690916650. Its totient is φ = 690916648.

The previous prime is 690916643. The next prime is 690916661. The reversal of 690916649 is 946619096.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 346146025 + 344770624 = 18605^2 + 18568^2 .

It is a cyclic number.

It is not a de Polignac number, because 690916649 - 2¹⁶ = 690851113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 690916597 and 690916606.

It is not a weakly prime, because it can be changed into another prime (690916643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345458324 + 345458325.

It is an arithmetic number, because the mean of its divisors is an integer number (345458325).

Almost surely, 2^690916649 is an apocalyptic number.

It is an amenable number.

690916649 is a deficient number, since it is larger than the sum of its proper divisors (1).

690916649 is an equidigital number, since it uses as much as digits as its factorization.

690916649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 629856, while the sum is 50.

The square root of 690916649 is about 26285.2933976397. The cubic root of 690916649 is about 884.0467244094.

The spelling of 690916649 in words is "six hundred ninety million, nine hundred sixteen thousand, six hundred forty-nine".