147805821 has 12 divisors (see below), whose sum is σ = 213676320. Its totient is φ = 98454600.

The previous prime is 147805811. The next prime is 147805873. The reversal of 147805821 is 128508741.

147805821 is a `hidden beast` number, since 1 + 4 + 78 + 0 + 582 + 1 = 666.

It is not a de Polignac number, because 147805821 - 2¹⁴ = 147789437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (147805811) 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 11 ways as a sum of consecutive naturals, for example, 5646 + ... + 18096.

It is an arithmetic number, because the mean of its divisors is an integer number (17806360).

Almost surely, 2^147805821 is an apocalyptic number.

It is an amenable number.

147805821 is a deficient number, since it is larger than the sum of its proper divisors (65870499).

147805821 is a wasteful number, since it uses less digits than its factorization.

147805821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13776 (or 13773 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 36.

The square root of 147805821 is about 12157.5417334262. The cubic root of 147805821 is about 528.7258118137.

The spelling of 147805821 in words is "one hundred forty-seven million, eight hundred five thousand, eight hundred twenty-one".