19720734 has 16 divisors (see below), whose sum is σ = 43027200. Its totient is φ = 5975960.

The previous prime is 19720733. The next prime is 19720781. The reversal of 19720734 is 43702791.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 19720695 and 19720704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19720733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149334 + ... + 149465.

It is an arithmetic number, because the mean of its divisors is an integer number (2689200).

Almost surely, 2^19720734 is an apocalyptic number.

19720734 is an abundant number, since it is smaller than the sum of its proper divisors (23306466).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19720734 is a wasteful number, since it uses less digits than its factorization.

19720734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298815.

The product of its (nonzero) digits is 10584, while the sum is 33.

The square root of 19720734 is about 4440.8033057095. The cubic root of 19720734 is about 270.1724275836.

The spelling of 19720734 in words is "nineteen million, seven hundred twenty thousand, seven hundred thirty-four".