30968821 has 4 divisors (see below), whose sum is σ = 33351052. Its totient is φ = 28586592.

The previous prime is 30968813. The next prime is 30968831. The reversal of 30968821 is 12886903.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12886903 = 1499 ⋅8597.

It can be written as a sum of positive squares in 2 ways, for example, as 3783025 + 27185796 = 1945^2 + 5214^2 .

It is a cyclic number.

It is not a de Polignac number, because 30968821 - 2³ = 30968813 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 (30968831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1191096 + ... + 1191121.

It is an arithmetic number, because the mean of its divisors is an integer number (8337763).

Almost surely, 2^30968821 is an apocalyptic number.

It is an amenable number.

30968821 is a deficient number, since it is larger than the sum of its proper divisors (2382231).

30968821 is a wasteful number, since it uses less digits than its factorization.

30968821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2382230.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 30968821 is about 5564.9637015887. The cubic root of 30968821 is about 314.0327125912.

The spelling of 30968821 in words is "thirty million, nine hundred sixty-eight thousand, eight hundred twenty-one".