19720440 has 48 divisors (see below), whose sum is σ = 64092600. Its totient is φ = 5258688.

The previous prime is 19720403. The next prime is 19720447. The reversal of 19720440 is 4402791.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19720447) 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 11 ways as a sum of consecutive naturals, for example, 27030 + ... + 27749.

Almost surely, 2^19720440 is an apocalyptic number.

19720440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19720440 is an abundant number, since it is smaller than the sum of its proper divisors (44372160).

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

19720440 is a wasteful number, since it uses less digits than its factorization.

19720440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54796 (or 54789 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 19720440 is about 4440.7702034670. The cubic root of 19720440 is about 270.1710849851.

The spelling of 19720440 in words is "nineteen million, seven hundred twenty thousand, four hundred forty".