19919718 has 48 divisors (see below), whose sum is σ = 53123616. Its totient is φ = 5253120.

The previous prime is 19919717. The next prime is 19919737. The reversal of 19919718 is 81791991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19919717) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4443 + ... + 7718.

It is an arithmetic number, because the mean of its divisors is an integer number (1106742).

Almost surely, 2^19919718 is an apocalyptic number.

19919718 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

19919718 is an abundant number, since it is smaller than the sum of its proper divisors (33203898).

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

19919718 is a wasteful number, since it uses less digits than its factorization.

19919718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12189 (or 12186 counting only the distinct ones).

The product of its digits is 40824, while the sum is 45.

The square root of 19919718 is about 4463.1511289671. The cubic root of 19919718 is about 271.0780764765.

The spelling of 19919718 in words is "nineteen million, nine hundred nineteen thousand, seven hundred eighteen".