208138920 has 256 divisors, whose sum is σ = 737510400. Its totient is φ = 46448640.

The previous prime is 208138907. The next prime is 208138933. The reversal of 208138920 is 29831802.

It is an interprime number because it is at equal distance from previous prime (208138907) and next prime (208138933).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1078344 + ... + 1078536.

It is an arithmetic number, because the mean of its divisors is an integer number (2880900).

Almost surely, 2^208138920 is an apocalyptic number.

208138920 is a gapful number since it is divisible by the number (20) 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 208138920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (368755200).

208138920 is an abundant number, since it is smaller than the sum of its proper divisors (529371480).

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

208138920 is a wasteful number, since it uses less digits than its factorization.

208138920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 276 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 208138920 is about 14427.0204824142. The cubic root of 208138920 is about 592.6310913626.

It can be divided in two parts, 208 and 138920, that added together give a triangular number (139128 = T₅₂₇).

The spelling of 208138920 in words is "two hundred eight million, one hundred thirty-eight thousand, nine hundred twenty".