690228761 has 4 divisors (see below), whose sum is σ = 690705252. Its totient is φ = 689752272.

The previous prime is 690228719. The next prime is 690228779. The reversal of 690228761 is 167822096.

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 421891600 + 268337161 = 20540^2 + 16381^2 .

It is a cyclic number.

It is not a de Polignac number, because 690228761 - 2⁶ = 690228697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (690228961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 236066 + ... + 238971.

It is an arithmetic number, because the mean of its divisors is an integer number (172676313).

Almost surely, 2^690228761 is an apocalyptic number.

It is an amenable number.

690228761 is a deficient number, since it is larger than the sum of its proper divisors (476491).

690228761 is a wasteful number, since it uses less digits than its factorization.

690228761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476490.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 690228761 is about 26272.2051034929. The cubic root of 690228761 is about 883.7532364922.

The spelling of 690228761 in words is "six hundred ninety million, two hundred twenty-eight thousand, seven hundred sixty-one".