188420990 has 16 divisors (see below), whose sum is σ = 342452448. Its totient is φ = 74636256.

The previous prime is 188420977. The next prime is 188420993. The reversal of 188420990 is 99024881.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (188420993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90437 + ... + 92496.

It is an arithmetic number, because the mean of its divisors is an integer number (21403278).

Almost surely, 2^188420990 is an apocalyptic number.

188420990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

188420990 is a deficient number, since it is larger than the sum of its proper divisors (154031458).

188420990 is a wasteful number, since it uses less digits than its factorization.

188420990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183043.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 188420990 is about 13726.6525416796. The cubic root of 188420990 is about 573.2927202919.

The spelling of 188420990 in words is "one hundred eighty-eight million, four hundred twenty thousand, nine hundred ninety".