30690821 has 8 divisors (see below), whose sum is σ = 35234304. Its totient is φ = 26187120.

The previous prime is 30690817. The next prime is 30690823. The reversal of 30690821 is 12809603.

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

It is a cyclic number.

It is not a de Polignac number, because 30690821 - 2² = 30690817 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30690823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8270 + ... + 11391.

It is an arithmetic number, because the mean of its divisors is an integer number (4404288).

Almost surely, 2^30690821 is an apocalyptic number.

It is an amenable number.

30690821 is a deficient number, since it is larger than the sum of its proper divisors (4543483).

30690821 is a wasteful number, since it uses less digits than its factorization.

30690821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19891.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 30690821 is about 5539.9296926947. The cubic root of 30690821 is about 313.0902202265.

The spelling of 30690821 in words is "thirty million, six hundred ninety thousand, eight hundred twenty-one".