19749216 has 24 divisors (see below), whose sum is σ = 51841944. Its totient is φ = 6583040.

The previous prime is 19749199. The next prime is 19749229. The reversal of 19749216 is 61294791.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×19749216² = 780063065229312, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 102765 + ... + 102956.

It is an arithmetic number, because the mean of its divisors is an integer number (2160081).

Almost surely, 2^19749216 is an apocalyptic number.

19749216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19749216 is an abundant number, since it is smaller than the sum of its proper divisors (32092728).

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

19749216 is a wasteful number, since it uses less digits than its factorization.

19749216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205734 (or 205726 counting only the distinct ones).

The product of its digits is 27216, while the sum is 39.

The square root of 19749216 is about 4444.0090008910. The cubic root of 19749216 is about 270.3024320328.

The spelling of 19749216 in words is "nineteen million, seven hundred forty-nine thousand, two hundred sixteen".