188139420 has 216 divisors, whose sum is σ = 674475984. Its totient is φ = 42319872.

The previous prime is 188139409. The next prime is 188139431. The reversal of 188139420 is 24931881.

It is an interprime number because it is at equal distance from previous prime (188139409) and next prime (188139431).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 731932 + ... + 732188.

It is an arithmetic number, because the mean of its divisors is an integer number (3122574).

Almost surely, 2^188139420 is an apocalyptic number.

188139420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 188139420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (337237992).

188139420 is an abundant number, since it is smaller than the sum of its proper divisors (486336564).

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

188139420 is a wasteful number, since it uses less digits than its factorization.

188139420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369 (or 357 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 188139420 is about 13716.3923828389. The cubic root of 188139420 is about 573.0070081286.

The spelling of 188139420 in words is "one hundred eighty-eight million, one hundred thirty-nine thousand, four hundred twenty".