1387228221 has 8 divisors (see below), whose sum is σ = 2055152960. Its totient is φ = 924818796.

The previous prime is 1387228217. The next prime is 1387228231. The reversal of 1387228221 is 1228227831.

It is not a de Polignac number, because 1387228221 - 2² = 1387228217 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 (1387228231) 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, 25689385 + ... + 25689438.

It is an arithmetic number, because the mean of its divisors is an integer number (256894120).

Almost surely, 2^1387228221 is an apocalyptic number.

It is an amenable number.

1387228221 is a deficient number, since it is larger than the sum of its proper divisors (667924739).

1387228221 is an equidigital number, since it uses as much as digits as its factorization.

1387228221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51378832 (or 51378826 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 1387228221 is about 37245.5127632847. The cubic root of 1387228221 is about 1115.2767237982.

The spelling of 1387228221 in words is "one billion, three hundred eighty-seven million, two hundred twenty-eight thousand, two hundred twenty-one".