208621540 has 24 divisors (see below), whose sum is σ = 449947512. Its totient is φ = 81192960.

The previous prime is 208621529. The next prime is 208621559. The reversal of 208621540 is 45126802.

It can be written as a sum of positive squares in 4 ways, for example, as 72012196 + 136609344 = 8486^2 + 11688^2 .

It is a junction number, because it is equal to n+sod(n) for n = 208621499 and 208621508.

It is an unprimeable number.

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, 140221 + ... + 141700.

It is an arithmetic number, because the mean of its divisors is an integer number (18747813).

Almost surely, 2^208621540 is an apocalyptic number.

208621540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

208621540 is an abundant number, since it is smaller than the sum of its proper divisors (241325972).

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

208621540 is a wasteful number, since it uses less digits than its factorization.

208621540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281967 (or 281965 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 208621540 is about 14443.7370510543. The cubic root of 208621540 is about 593.0887902181.

The spelling of 208621540 in words is "two hundred eight million, six hundred twenty-one thousand, five hundred forty".