690507121 has 2 divisors, whose sum is σ = 690507122. Its totient is φ = 690507120.

The previous prime is 690507119. The next prime is 690507131. The reversal of 690507121 is 121705096.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 435306496 + 255200625 = 20864^2 + 15975^2 .

It is a cyclic number.

It is not a de Polignac number, because 690507121 - 2¹ = 690507119 is a prime.

Together with 690507119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (690507131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345253560 + 345253561.

It is an arithmetic number, because the mean of its divisors is an integer number (345253561).

Almost surely, 2^690507121 is an apocalyptic number.

It is an amenable number.

690507121 is a deficient number, since it is larger than the sum of its proper divisors (1).

690507121 is an equidigital number, since it uses as much as digits as its factorization.

690507121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 690507121 is about 26277.5021834268. The cubic root of 690507121 is about 883.8720224670.

The spelling of 690507121 in words is "six hundred ninety million, five hundred seven thousand, one hundred twenty-one".