30993945 has 16 divisors (see below), whose sum is σ = 49972032. Its totient is φ = 16402880.

The previous prime is 30993931. The next prime is 30993947. The reversal of 30993945 is 54939903.

It is a happy number.

It is not a de Polignac number, because 30993945 - 2⁴ = 30993929 is a prime.

It is a super-3 number, since 3×30993945³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 30993897 and 30993906.

It is not an unprimeable number, because it can be changed into a prime (30993947) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5922 + ... + 9851.

It is an arithmetic number, because the mean of its divisors is an integer number (3123252).

Almost surely, 2^30993945 is an apocalyptic number.

It is an amenable number.

30993945 is a deficient number, since it is larger than the sum of its proper divisors (18978087).

30993945 is a wasteful number, since it uses less digits than its factorization.

30993945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15912.

The product of its (nonzero) digits is 131220, while the sum is 42.

The square root of 30993945 is about 5567.2205812236. The cubic root of 30993945 is about 314.1176111548.

The spelling of 30993945 in words is "thirty million, nine hundred ninety-three thousand, nine hundred forty-five".