19990973 has 4 divisors (see below), whose sum is σ = 20272608. Its totient is φ = 19709340.

The previous prime is 19990937. The next prime is 19991003. The reversal of 19990973 is 37909991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19990973 - 2¹² = 19986877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19990573) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140711 + ... + 140852.

It is an arithmetic number, because the mean of its divisors is an integer number (5068152).

Almost surely, 2^19990973 is an apocalyptic number.

It is an amenable number.

19990973 is a deficient number, since it is larger than the sum of its proper divisors (281635).

19990973 is an equidigital number, since it uses as much as digits as its factorization.

19990973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281634.

The product of its (nonzero) digits is 137781, while the sum is 47.

The square root of 19990973 is about 4471.1265918111. The cubic root of 19990973 is about 271.4009171008.

The spelling of 19990973 in words is "nineteen million, nine hundred ninety thousand, nine hundred seventy-three".