851157491 has 2 divisors, whose sum is σ = 851157492. Its totient is φ = 851157490.

The previous prime is 851157467. The next prime is 851157539. The reversal of 851157491 is 194751158.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 851157491 - 2¹⁴ = 851141107 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (851157691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 425578745 + 425578746.

It is an arithmetic number, because the mean of its divisors is an integer number (425578746).

Almost surely, 2^851157491 is an apocalyptic number.

851157491 is a deficient number, since it is larger than the sum of its proper divisors (1).

851157491 is an equidigital number, since it uses as much as digits as its factorization.

851157491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 41.

The square root of 851157491 is about 29174.6035277260. The cubic root of 851157491 is about 947.6980242976.

The spelling of 851157491 in words is "eight hundred fifty-one million, one hundred fifty-seven thousand, four hundred ninety-one".