1394021221 has 4 divisors (see below), whose sum is σ = 1395656332. Its totient is φ = 1392386112.

The previous prime is 1394021219. The next prime is 1394021231. The reversal of 1394021221 is 1221204931.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 221712100 + 1172309121 = 14890^2 + 34239^2 .

It is a cyclic number.

It is not a de Polignac number, because 1394021221 - 2¹ = 1394021219 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 (1394021201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 816276 + ... + 817981.

It is an arithmetic number, because the mean of its divisors is an integer number (348914083).

Almost surely, 2^1394021221 is an apocalyptic number.

It is an amenable number.

1394021221 is a deficient number, since it is larger than the sum of its proper divisors (1635111).

1394021221 is an equidigital number, since it uses as much as digits as its factorization.

1394021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1635110.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1394021221 is about 37336.5935912745. The cubic root of 1394021221 is about 1117.0941950189.

The spelling of 1394021221 in words is "one billion, three hundred ninety-four million, twenty-one thousand, two hundred twenty-one".