19969840 has 60 divisors (see below), whose sum is σ = 51059232. Its totient is φ = 7258240.

The previous prime is 19969799. The next prime is 19969843. The reversal of 19969840 is 4896991.

It is not an unprimeable number, because it can be changed into a prime (19969843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8649 + ... + 10711.

Almost surely, 2^19969840 is an apocalyptic number.

19969840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19969840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25529616).

19969840 is an abundant number, since it is smaller than the sum of its proper divisors (31089392).

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

19969840 is a wasteful number, since it uses less digits than its factorization.

19969840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2098 (or 2081 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 19969840 is about 4468.7626922897. The cubic root of 19969840 is about 271.3052482902.

The spelling of 19969840 in words is "nineteen million, nine hundred sixty-nine thousand, eight hundred forty".