19161216 has 48 divisors (see below), whose sum is σ = 55141710. Its totient is φ = 6386688.

The previous prime is 19161209. The next prime is 19161217. The reversal of 19161216 is 61216191.

It can be written as a sum of positive squares in only one way, i.e., 18455616 + 705600 = 4296^2 + 840^2 .

It is a tau number, because it is divible by the number of its divisors (48).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 19161216.

It is not an unprimeable number, because it can be changed into a prime (19161217) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7165 + ... + 9468.

Almost surely, 2^19161216 is an apocalyptic number.

19161216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19161216 is an abundant number, since it is smaller than the sum of its proper divisors (35980494).

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

19161216 is a wasteful number, since it uses less digits than its factorization.

19161216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16653 (or 16638 counting only the distinct ones).

The product of its digits is 648, while the sum is 27.

The square root of 19161216 is about 4377.3526245894. The cubic root of 19161216 is about 267.5927578861.

The spelling of 19161216 in words is "nineteen million, one hundred sixty-one thousand, two hundred sixteen".