19921008 has 40 divisors (see below), whose sum is σ = 54492048. Its totient is φ = 6249472.

The previous prime is 19920973. The next prime is 19921021. The reversal of 19921008 is 80012991.

It is a congruent number.

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, 11391 + ... + 13022.

Almost surely, 2^19921008 is an apocalyptic number.

It is an amenable number.

19921008 is an abundant number, since it is smaller than the sum of its proper divisors (34571040).

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

19921008 is a wasteful number, since it uses less digits than its factorization.

19921008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24441 (or 24435 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 19921008 is about 4463.2956433559. The cubic root of 19921008 is about 271.0839280180.

Adding to 19921008 its reverse (80012991), we get a palindrome (99933999).

The spelling of 19921008 in words is "nineteen million, nine hundred twenty-one thousand, eight".