1816239157 has 2 divisors, whose sum is σ = 1816239158. Its totient is φ = 1816239156.

The previous prime is 1816239119. The next prime is 1816239167. The reversal of 1816239157 is 7519326181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1729395396 + 86843761 = 41586^2 + 9319^2 .

It is an emirp because it is prime and its reverse (7519326181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1816239157 - 2¹⁵ = 1816206389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1816239107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 908119578 + 908119579.

It is an arithmetic number, because the mean of its divisors is an integer number (908119579).

Almost surely, 2^1816239157 is an apocalyptic number.

It is an amenable number.

1816239157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1816239157 is an equidigital number, since it uses as much as digits as its factorization.

1816239157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The square root of 1816239157 is about 42617.3574614851. The cubic root of 1816239157 is about 1220.0875949379.

The spelling of 1816239157 in words is "one billion, eight hundred sixteen million, two hundred thirty-nine thousand, one hundred fifty-seven".