812400091 has 4 divisors (see below), whose sum is σ = 812464000. Its totient is φ = 812336184.

The previous prime is 812400073. The next prime is 812400101. The reversal of 812400091 is 190004218.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 812400091 - 2¹¹ = 812398043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (812400031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5691 + ... + 40708.

It is an arithmetic number, because the mean of its divisors is an integer number (203116000).

Almost surely, 2^812400091 is an apocalyptic number.

812400091 is a deficient number, since it is larger than the sum of its proper divisors (63909).

812400091 is a wasteful number, since it uses less digits than its factorization.

812400091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63908.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 812400091 is about 28502.6330538075. The cubic root of 812400091 is about 933.0895403076.

The spelling of 812400091 in words is "eight hundred twelve million, four hundred thousand, ninety-one".