1321787221 has 8 divisors (see below), whose sum is σ = 1326924000. Its totient is φ = 1316661360.

The previous prime is 1321787219. The next prime is 1321787267. The reversal of 1321787221 is 1227871231.

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

It is a cyclic number.

It is not a de Polignac number, because 1321787221 - 2¹ = 1321787219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321787321) 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, 301755 + ... + 306103.

It is an arithmetic number, because the mean of its divisors is an integer number (165865500).

Almost surely, 2^1321787221 is an apocalyptic number.

It is an amenable number.

1321787221 is a deficient number, since it is larger than the sum of its proper divisors (5136779).

1321787221 is an equidigital number, since it uses as much as digits as its factorization.

1321787221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5459.

The product of its digits is 9408, while the sum is 34.

The square root of 1321787221 is about 36356.3917489071. The cubic root of 1321787221 is about 1097.4561660774.

The spelling of 1321787221 in words is "one billion, three hundred twenty-one million, seven hundred eighty-seven thousand, two hundred twenty-one".