30121890 has 16 divisors (see below), whose sum is σ = 72292608. Its totient is φ = 8032496.

The previous prime is 30121879. The next prime is 30121901. The reversal of 30121890 is 9812103.

It is an interprime number because it is at equal distance from previous prime (30121879) and next prime (30121901).

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 30121890.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 502002 + ... + 502061.

It is an arithmetic number, because the mean of its divisors is an integer number (4518288).

Almost surely, 2^30121890 is an apocalyptic number.

30121890 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

30121890 is an abundant number, since it is smaller than the sum of its proper divisors (42170718).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

30121890 is a wasteful number, since it uses less digits than its factorization.

30121890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1004073.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 30121890 is about 5488.3412794760. The cubic root of 30121890 is about 311.1435047997.

Adding to 30121890 its reverse (9812103), we get a palindrome (39933993).

The spelling of 30121890 in words is "thirty million, one hundred twenty-one thousand, eight hundred ninety".