651609397 has 2 divisors, whose sum is σ = 651609398. Its totient is φ = 651609396.

The previous prime is 651609379. The next prime is 651609403. The reversal of 651609397 is 793906156.

Together with previous prime (651609379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 433722276 + 217887121 = 20826^2 + 14761^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-651609397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (651609307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325804698 + 325804699.

It is an arithmetic number, because the mean of its divisors is an integer number (325804699).

Almost surely, 2^651609397 is an apocalyptic number.

It is an amenable number.

651609397 is a deficient number, since it is larger than the sum of its proper divisors (1).

651609397 is an equidigital number, since it uses as much as digits as its factorization.

651609397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 306180, while the sum is 46.

The square root of 651609397 is about 25526.6409266868. The cubic root of 651609397 is about 866.9534507685.

The spelling of 651609397 in words is "six hundred fifty-one million, six hundred nine thousand, three hundred ninety-seven".