690807121 has 4 divisors (see below), whose sum is σ = 731442852. Its totient is φ = 650171392.

The previous prime is 690807119. The next prime is 690807133. The reversal of 690807121 is 121708096.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 242892225 + 447914896 = 15585^2 + 21164^2 .

It is not a de Polignac number, because 690807121 - 2¹ = 690807119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (690807181) 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 in 3 ways as a sum of consecutive naturals, for example, 20317840 + ... + 20317873.

It is an arithmetic number, because the mean of its divisors is an integer number (182860713).

Almost surely, 2^690807121 is an apocalyptic number.

It is an amenable number.

690807121 is a deficient number, since it is larger than the sum of its proper divisors (40635731).

690807121 is a wasteful number, since it uses less digits than its factorization.

690807121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40635730.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 690807121 is about 26283.2098686595. The cubic root of 690807121 is about 884.0000072514. Note that the first 5 decimals are identical.

The spelling of 690807121 in words is "six hundred ninety million, eight hundred seven thousand, one hundred twenty-one".