1287219221 has 4 divisors (see below), whose sum is σ = 1314606912. Its totient is φ = 1259831532.

The previous prime is 1287219217. The next prime is 1287219247. The reversal of 1287219221 is 1229127821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1229127821 = 797 ⋅1542193.

It is a cyclic number.

It is not a de Polignac number, because 1287219221 - 2² = 1287219217 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 (1287219211) 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, 13693775 + ... + 13693868.

It is an arithmetic number, because the mean of its divisors is an integer number (328651728).

Almost surely, 2^1287219221 is an apocalyptic number.

It is an amenable number.

1287219221 is a deficient number, since it is larger than the sum of its proper divisors (27387691).

1287219221 is an equidigital number, since it uses as much as digits as its factorization.

1287219221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27387690.

The product of its digits is 8064, while the sum is 35.

The square root of 1287219221 is about 35877.8374627011. The cubic root of 1287219221 is about 1087.8044690454.

The spelling of 1287219221 in words is "one billion, two hundred eighty-seven million, two hundred nineteen thousand, two hundred twenty-one".