1388322221 has 32 divisors (see below), whose sum is σ = 1749081600. Its totient is φ = 1082465280.

The previous prime is 1388322211. The next prime is 1388322223. The reversal of 1388322221 is 1222238831.

It is not a de Polignac number, because 1388322221 - 2⁶ = 1388322157 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 (1388322223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 188435 + ... + 195663.

It is an arithmetic number, because the mean of its divisors is an integer number (54658800).

Almost surely, 2^1388322221 is an apocalyptic number.

1388322221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1388322221 is a deficient number, since it is larger than the sum of its proper divisors (360759379).

1388322221 is a wasteful number, since it uses less digits than its factorization.

1388322221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7349.

The product of its digits is 9216, while the sum is 32.

The square root of 1388322221 is about 37260.1962018452. The cubic root of 1388322221 is about 1115.5698243665.

The spelling of 1388322221 in words is "one billion, three hundred eighty-eight million, three hundred twenty-two thousand, two hundred twenty-one".