30021993 has 6 divisors (see below), whose sum is σ = 43365114. Its totient is φ = 20014656.

The previous prime is 30021977. The next prime is 30022007. The reversal of 30021993 is 39912003.

It can be written as a sum of positive squares in only one way, i.e., 17040384 + 12981609 = 4128^2 + 3603^2 .

It is not a de Polignac number, because 30021993 - 2⁴ = 30021977 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (30021193) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1667880 + ... + 1667897.

It is an arithmetic number, because the mean of its divisors is an integer number (7227519).

Almost surely, 2^30021993 is an apocalyptic number.

It is an amenable number.

30021993 is a deficient number, since it is larger than the sum of its proper divisors (13343121).

30021993 is a wasteful number, since it uses less digits than its factorization.

30021993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3335783 (or 3335780 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 27.

The square root of 30021993 is about 5479.2328842640. The cubic root of 30021993 is about 310.7991624531.

Adding to 30021993 its reverse (39912003), we get a palindrome (69933996).

The spelling of 30021993 in words is "thirty million, twenty-one thousand, nine hundred ninety-three".