811540819 has 2 divisors, whose sum is σ = 811540820. Its totient is φ = 811540818.

The previous prime is 811540799. The next prime is 811540841. The reversal of 811540819 is 918045118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 811540819 - 2²⁷ = 677323091 is a prime.

It is a super-2 number, since 2×811540819² = 1317197001806381522, which contains 22 as substring.

It is equal to p_41709349 and since 811540819 and 41709349 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (811540879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405770409 + 405770410.

It is an arithmetic number, because the mean of its divisors is an integer number (405770410).

Almost surely, 2^811540819 is an apocalyptic number.

811540819 is a deficient number, since it is larger than the sum of its proper divisors (1).

811540819 is an equidigital number, since it uses as much as digits as its factorization.

811540819 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11520, while the sum is 37.

The square root of 811540819 is about 28487.5555111350. Note that the first 4 decimals coincide. The cubic root of 811540819 is about 932.7604493545.

The spelling of 811540819 in words is "eight hundred eleven million, five hundred forty thousand, eight hundred nineteen".