19221216 has 48 divisors (see below), whose sum is σ = 57665664. Its totient is φ = 5491584.

The previous prime is 19221157. The next prime is 19221221. The reversal of 19221216 is 61212291.

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

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13630 + ... + 14973.

It is an arithmetic number, because the mean of its divisors is an integer number (1201368).

Almost surely, 2^19221216 is an apocalyptic number.

19221216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19221216 is an abundant number, since it is smaller than the sum of its proper divisors (38444448).

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

19221216 is a wasteful number, since it uses less digits than its factorization.

19221216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28623 (or 28615 counting only the distinct ones).

The product of its digits is 432, while the sum is 24.

The square root of 19221216 is about 4384.2007253318. The cubic root of 19221216 is about 267.8717735145.

The spelling of 19221216 in words is "nineteen million, two hundred twenty-one thousand, two hundred sixteen".