19999973 has 8 divisors (see below), whose sum is σ = 24201792. Its totient is φ = 16134336.

The previous prime is 19999963. The next prime is 19999981. The reversal of 19999973 is 37999991.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 19999973 - 2⁶ = 19999909 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 (19999963) 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, 83915 + ... + 84152.

It is an arithmetic number, because the mean of its divisors is an integer number (3025224).

Almost surely, 2^19999973 is an apocalyptic number.

It is an amenable number.

19999973 is a deficient number, since it is larger than the sum of its proper divisors (4201819).

19999973 is a wasteful number, since it uses less digits than its factorization.

19999973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168091.

The product of its digits is 1240029, while the sum is 56.

The square root of 19999973 is about 4472.1329363068. The cubic root of 19999973 is about 271.4416395106.

The spelling of 19999973 in words is "nineteen million, nine hundred ninety-nine thousand, nine hundred seventy-three".