690256321 has 16 divisors (see below), whose sum is σ = 746554320. Its totient is φ = 635852800.

The previous prime is 690256291. The next prime is 690256331. The reversal of 690256321 is 123652096.

It can be written as a sum of positive squares in 8 ways, for example, as 5125696 + 685130625 = 2264^2 + 26175^2 .

It is a cyclic number.

It is not a de Polignac number, because 690256321 - 2¹¹ = 690254273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (690256331) 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 15 ways as a sum of consecutive naturals, for example, 150555 + ... + 155071.

It is an arithmetic number, because the mean of its divisors is an integer number (46659645).

Almost surely, 2^690256321 is an apocalyptic number.

It is an amenable number.

690256321 is a deficient number, since it is larger than the sum of its proper divisors (56297999).

690256321 is a wasteful number, since it uses less digits than its factorization.

690256321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4724.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 690256321 is about 26272.7296069518. The cubic root of 690256321 is about 883.7649987351.

The spelling of 690256321 in words is "six hundred ninety million, two hundred fifty-six thousand, three hundred twenty-one".