19921604 has 6 divisors (see below), whose sum is σ = 34862814. Its totient is φ = 9960800.

The previous prime is 19921589. The next prime is 19921607. The reversal of 19921604 is 40612991.

It can be written as a sum of positive squares in only one way, i.e., 19784704 + 136900 = 4448^2 + 370^2 .

It is not an unprimeable number, because it can be changed into a prime (19921607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2490197 + ... + 2490204.

It is an arithmetic number, because the mean of its divisors is an integer number (5810469).

Almost surely, 2^19921604 is an apocalyptic number.

It is an amenable number.

19921604 is a deficient number, since it is larger than the sum of its proper divisors (14941210).

19921604 is a wasteful number, since it uses less digits than its factorization.

19921604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4980405 (or 4980403 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 19921604 is about 4463.3624096638. The cubic root of 19921604 is about 271.0866314356.

The spelling of 19921604 in words is "nineteen million, nine hundred twenty-one thousand, six hundred four".