851567491 has 2 divisors, whose sum is σ = 851567492. Its totient is φ = 851567490.

The previous prime is 851567471. The next prime is 851567501. The reversal of 851567491 is 194765158.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 851567491 - 2⁵ = 851567459 is a prime.

It is not a weakly prime, because it can be changed into another prime (851567401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425783745 + 425783746.

It is an arithmetic number, because the mean of its divisors is an integer number (425783746).

Almost surely, 2^851567491 is an apocalyptic number.

851567491 is a deficient number, since it is larger than the sum of its proper divisors (1).

851567491 is an equidigital number, since it uses as much as digits as its factorization.

851567491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 302400, while the sum is 46.

The square root of 851567491 is about 29181.6293410769. The cubic root of 851567491 is about 947.8501676326.

The spelling of 851567491 in words is "eight hundred fifty-one million, five hundred sixty-seven thousand, four hundred ninety-one".