806178021 has 16 divisors (see below), whose sum is σ = 1173132288. Its totient is φ = 488380400.

The previous prime is 806178011. The next prime is 806178049. The reversal of 806178021 is 120871608.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 806178021 - 2¹⁹ = 805653733 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (806178011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107620 + ... + 114866.

It is an arithmetic number, because the mean of its divisors is an integer number (73320768).

Almost surely, 2^806178021 is an apocalyptic number.

It is an amenable number.

806178021 is a deficient number, since it is larger than the sum of its proper divisors (366954267).

806178021 is a wasteful number, since it uses less digits than its factorization.

806178021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10632.

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 806178021 is about 28393.2742211954. The cubic root of 806178021 is about 930.7012943672.

The spelling of 806178021 in words is "eight hundred six million, one hundred seventy-eight thousand, twenty-one".