19081221 has 8 divisors (see below), whose sum is σ = 25584480. Its totient is φ = 12649392.

The previous prime is 19081211. The next prime is 19081241. The reversal of 19081221 is 12218091.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 19081221 - 2⁵ = 19081189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19081191 and 19081200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19081211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17230 + ... + 18303.

It is an arithmetic number, because the mean of its divisors is an integer number (3198060).

Almost surely, 2^19081221 is an apocalyptic number.

It is an amenable number.

19081221 is a deficient number, since it is larger than the sum of its proper divisors (6503259).

19081221 is a wasteful number, since it uses less digits than its factorization.

19081221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35715.

The product of its (nonzero) digits is 288, while the sum is 24.

The square root of 19081221 is about 4368.2056957062. The cubic root of 19081221 is about 267.2198528656.

The spelling of 19081221 in words is "nineteen million, eighty-one thousand, two hundred twenty-one".