19921899 has 8 divisors (see below), whose sum is σ = 27960640. Its totient is φ = 12582216.

The previous prime is 19921877. The next prime is 19921901. The reversal of 19921899 is 99812991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19921899 - 2⁹ = 19921387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19921829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 174697 + ... + 174810.

It is an arithmetic number, because the mean of its divisors is an integer number (3495080).

Almost surely, 2^19921899 is an apocalyptic number.

19921899 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

19921899 is a deficient number, since it is larger than the sum of its proper divisors (8038741).

19921899 is a wasteful number, since it uses less digits than its factorization.

19921899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349529.

The product of its digits is 104976, while the sum is 48.

The square root of 19921899 is about 4463.3954563762. The cubic root of 19921899 is about 271.0879695166.

The spelling of 19921899 in words is "nineteen million, nine hundred twenty-one thousand, eight hundred ninety-nine".