18919930 has 16 divisors (see below), whose sum is σ = 34247304. Its totient is φ = 7525440.

The previous prime is 18919907. The next prime is 18919939. The reversal of 18919930 is 3991981.

It can be written as a sum of positive squares in 4 ways, for example, as 14891881 + 4028049 = 3859^2 + 2007^2 .

It is not an unprimeable number, because it can be changed into a prime (18919939) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3417 + ... + 7036.

Almost surely, 2^18919930 is an apocalyptic number.

18919930 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18919930 is a deficient number, since it is larger than the sum of its proper divisors (15327374).

18919930 is a wasteful number, since it uses less digits than its factorization.

18919930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10641.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 18919930 is about 4349.7045876703. The cubic root of 18919930 is about 266.4647968735.

The spelling of 18919930 in words is "eighteen million, nine hundred nineteen thousand, nine hundred thirty".