1388217420 has 48 divisors (see below), whose sum is σ = 4318900320. Its totient is φ = 370191168.

The previous prime is 1388217403. The next prime is 1388217451. The reversal of 1388217420 is 247128831.

1388217420 is a `hidden beast` number, since 13 + 8 + 8 + 217 + 420 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1284847 + ... + 1285926.

It is an arithmetic number, because the mean of its divisors is an integer number (89977090).

Almost surely, 2^1388217420 is an apocalyptic number.

1388217420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1388217420 is an abundant number, since it is smaller than the sum of its proper divisors (2930682900).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1388217420 is a wasteful number, since it uses less digits than its factorization.

1388217420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2570791 (or 2570783 counting only the distinct ones).

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

The square root of 1388217420 is about 37258.7898354200. The cubic root of 1388217420 is about 1115.5417531274.

The spelling of 1388217420 in words is "one billion, three hundred eighty-eight million, two hundred seventeen thousand, four hundred twenty".