1388842221 has 32 divisors (see below), whose sum is σ = 2102880640. Its totient is φ = 808268544.

The previous prime is 1388842193. The next prime is 1388842223. The reversal of 1388842221 is 1222488831.

It is not a de Polignac number, because 1388842221 - 2⁷ = 1388842093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1388842221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388842223) 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, 541875 + ... + 544431.

It is an arithmetic number, because the mean of its divisors is an integer number (65715020).

Almost surely, 2^1388842221 is an apocalyptic number.

It is an amenable number.

1388842221 is a deficient number, since it is larger than the sum of its proper divisors (714038419).

1388842221 is a wasteful number, since it uses less digits than its factorization.

1388842221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3325.

The product of its digits is 49152, while the sum is 39.

The square root of 1388842221 is about 37267.1735043054. The cubic root of 1388842221 is about 1115.7090869213.

The spelling of 1388842221 in words is "one billion, three hundred eighty-eight million, eight hundred forty-two thousand, two hundred twenty-one".