651137891 has 2 divisors, whose sum is σ = 651137892. Its totient is φ = 651137890.

The previous prime is 651137887. The next prime is 651137939. The reversal of 651137891 is 198731156.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 651137891 - 2² = 651137887 is a prime.

It is not a weakly prime, because it can be changed into another prime (651137191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325568945 + 325568946.

It is an arithmetic number, because the mean of its divisors is an integer number (325568946).

Almost surely, 2^651137891 is an apocalyptic number.

651137891 is a deficient number, since it is larger than the sum of its proper divisors (1).

651137891 is an equidigital number, since it uses as much as digits as its factorization.

651137891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 41.

The square root of 651137891 is about 25517.4036884633. The cubic root of 651137891 is about 866.7442904997.

The spelling of 651137891 in words is "six hundred fifty-one million, one hundred thirty-seven thousand, eight hundred ninety-one".