208139040 has 72 divisors (see below), whose sum is σ = 710279388. Its totient is φ = 55503360.

The previous prime is 208139039. The next prime is 208139069. The reversal of 208139040 is 40931802.

208139040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 196112016 + 12027024 = 14004^2 + 3468^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 208138995 and 208139013.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70831 + ... + 73710.

Almost surely, 2^208139040 is an apocalyptic number.

208139040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

208139040 is an abundant number, since it is smaller than the sum of its proper divisors (502140348).

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

208139040 is a wasteful number, since it uses less digits than its factorization.

208139040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144562 (or 144551 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 208139040 is about 14427.0246412765. The cubic root of 208139040 is about 592.6312052540.

The spelling of 208139040 in words is "two hundred eight million, one hundred thirty-nine thousand, forty".