19720031 has 4 divisors (see below), whose sum is σ = 19741392. Its totient is φ = 19698672.

The previous prime is 19720027. The next prime is 19720049. The reversal of 19720031 is 13002791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19720031 - 2² = 19720027 is a prime.

It is a super-2 number, since 2×19720031² = 777759245281922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19719979 and 19720006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19720021) 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, 9230 + ... + 11163.

It is an arithmetic number, because the mean of its divisors is an integer number (4935348).

Almost surely, 2^19720031 is an apocalyptic number.

19720031 is a deficient number, since it is larger than the sum of its proper divisors (21361).

19720031 is an equidigital number, since it uses as much as digits as its factorization.

19720031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21360.

The product of its (nonzero) digits is 378, while the sum is 23.

The square root of 19720031 is about 4440.7241526580. The cubic root of 19720031 is about 270.1692171982.

The spelling of 19720031 in words is "nineteen million, seven hundred twenty thousand, thirty-one".