651641491 has 2 divisors, whose sum is σ = 651641492. Its totient is φ = 651641490.

The previous prime is 651641453. The next prime is 651641527. The reversal of 651641491 is 194146156.

651641491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-651641491 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 651641491.

It is not a weakly prime, because it can be changed into another prime (651641401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325820745 + 325820746.

It is an arithmetic number, because the mean of its divisors is an integer number (325820746).

Almost surely, 2^651641491 is an apocalyptic number.

651641491 is a deficient number, since it is larger than the sum of its proper divisors (1).

651641491 is an equidigital number, since it uses as much as digits as its factorization.

651641491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 37.

The square root of 651641491 is about 25527.2695563000. The cubic root of 651641491 is about 866.9676840128.

The spelling of 651641491 in words is "six hundred fifty-one million, six hundred forty-one thousand, four hundred ninety-one".