30921198 has 128 divisors (see below), whose sum is σ = 84934656. Its totient is φ = 7257600.

The previous prime is 30921161. The next prime is 30921211. The reversal of 30921198 is 89112903.

It is a super-2 number, since 2×30921198² = 1912240971510408, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 243411 + ... + 243537.

It is an arithmetic number, because the mean of its divisors is an integer number (663552).

Almost surely, 2^30921198 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 30921198, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42467328).

30921198 is an abundant number, since it is smaller than the sum of its proper divisors (54013458).

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

30921198 is a wasteful number, since it uses less digits than its factorization.

30921198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 30921198 is about 5560.6832314024. The cubic root of 30921198 is about 313.8716597232.

The spelling of 30921198 in words is "thirty million, nine hundred twenty-one thousand, one hundred ninety-eight".