30821813 has 8 divisors (see below), whose sum is σ = 33746016. Its totient is φ = 27918000.

The previous prime is 30821803. The next prime is 30821827. The reversal of 30821813 is 31812803.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-30821813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30821803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1838 + ... + 8063.

It is an arithmetic number, because the mean of its divisors is an integer number (4218252).

Almost surely, 2^30821813 is an apocalyptic number.

It is an amenable number.

30821813 is a deficient number, since it is larger than the sum of its proper divisors (2924203).

30821813 is a wasteful number, since it uses less digits than its factorization.

30821813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10195.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 30821813 is about 5551.7396372669. The cubic root of 30821813 is about 313.5350231818.

The spelling of 30821813 in words is "thirty million, eight hundred twenty-one thousand, eight hundred thirteen".