812778005 has 32 divisors (see below), whose sum is σ = 1072667904. Its totient is φ = 587575296.

The previous prime is 812777971. The next prime is 812778013. The reversal of 812778005 is 500877218.

It is a cyclic number.

It is not a de Polignac number, because 812778005 - 2⁶ = 812777941 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 812778005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 840032 + ... + 840998.

It is an arithmetic number, because the mean of its divisors is an integer number (33520872).

Almost surely, 2^812778005 is an apocalyptic number.

It is an amenable number.

812778005 is a deficient number, since it is larger than the sum of its proper divisors (259889899).

812778005 is a wasteful number, since it uses less digits than its factorization.

812778005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1245.

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 812778005 is about 28509.2617407045. The cubic root of 812778005 is about 933.2342034031.

The spelling of 812778005 in words is "eight hundred twelve million, seven hundred seventy-eight thousand, five".