30705021 has 32 divisors (see below), whose sum is σ = 46941440. Its totient is φ = 19828800.

The previous prime is 30705019. The next prime is 30705049. The reversal of 30705021 is 12050703.

It is not a de Polignac number, because 30705021 - 2¹ = 30705019 is a prime.

It is a super-2 number, since 2×30705021² = 1885596629220882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 30704985 and 30705003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30705061) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 169551 + ... + 169731.

It is an arithmetic number, because the mean of its divisors is an integer number (1466920).

Almost surely, 2^30705021 is an apocalyptic number.

It is an amenable number.

30705021 is a deficient number, since it is larger than the sum of its proper divisors (16236419).

30705021 is a wasteful number, since it uses less digits than its factorization.

30705021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354 (or 348 counting only the distinct ones).

The product of its (nonzero) digits is 210, while the sum is 18.

The square root of 30705021 is about 5541.2111491983. The cubic root of 30705021 is about 313.1384995435.

Adding to 30705021 its reverse (12050703), we get a palindrome (42755724).

The spelling of 30705021 in words is "thirty million, seven hundred five thousand, twenty-one".