19992918 has 64 divisors (see below), whose sum is σ = 46904832. Its totient is φ = 5614080.

The previous prime is 19992899. The next prime is 19992937. The reversal of 19992918 is 81929991.

It is an interprime number because it is at equal distance from previous prime (19992899) and next prime (19992937).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115480 + ... + 115652.

It is an arithmetic number, because the mean of its divisors is an integer number (732888).

Almost surely, 2^19992918 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19992918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23452416).

19992918 is an abundant number, since it is smaller than the sum of its proper divisors (26911914).

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

19992918 is a wasteful number, since it uses less digits than its factorization.

19992918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309.

The product of its digits is 104976, while the sum is 48.

The square root of 19992918 is about 4471.3440932230. The cubic root of 19992918 is about 271.4097187011.

It can be divided in two parts, 19992 and 918, that multiplied together give a square (18352656 = 4284²).

The spelling of 19992918 in words is "nineteen million, nine hundred ninety-two thousand, nine hundred eighteen".