188421408 has 72 divisors (see below), whose sum is σ = 612376128. Its totient is φ = 53834112.

The previous prime is 188421407. The next prime is 188421463. The reversal of 188421408 is 804124881.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is not an unprimeable number, because it can be changed into a prime (188421407) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44716 + ... + 48747.

It is an arithmetic number, because the mean of its divisors is an integer number (8505224).

Almost surely, 2^188421408 is an apocalyptic number.

188421408 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

188421408 is an abundant number, since it is smaller than the sum of its proper divisors (423954720).

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

188421408 is a wasteful number, since it uses less digits than its factorization.

188421408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93486 (or 93475 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 36.

The square root of 188421408 is about 13726.6677675246. The cubic root of 188421408 is about 573.2931442294.

It can be divided in two parts, 18 and 8421408, that multiplied together give a square (151585344 = 12312²).

The spelling of 188421408 in words is "one hundred eighty-eight million, four hundred twenty-one thousand, four hundred eight".