19701221 has 8 divisors (see below), whose sum is σ = 20196000. Its totient is φ = 19211920.

The previous prime is 19701203. The next prime is 19701223. The reversal of 19701221 is 12210791.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19701221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19701223) 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, 6455 + ... + 9003.

It is an arithmetic number, because the mean of its divisors is an integer number (2524500).

Almost surely, 2^19701221 is an apocalyptic number.

It is an amenable number.

19701221 is a deficient number, since it is larger than the sum of its proper divisors (494779).

19701221 is a wasteful number, since it uses less digits than its factorization.

19701221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2739.

The product of its (nonzero) digits is 252, while the sum is 23.

The square root of 19701221 is about 4438.6057495569. The cubic root of 19701221 is about 270.0832893478.

The spelling of 19701221 in words is "nineteen million, seven hundred one thousand, two hundred twenty-one".