208421390 has 16 divisors (see below), whose sum is σ = 375937632. Its totient is φ = 83195424.

The previous prime is 208421363. The next prime is 208421419. The reversal of 208421390 is 93124802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16529 + ... + 26268.

It is an arithmetic number, because the mean of its divisors is an integer number (23496102).

Almost surely, 2^208421390 is an apocalyptic number.

208421390 is a deficient number, since it is larger than the sum of its proper divisors (167516242).

208421390 is a wasteful number, since it uses less digits than its factorization.

208421390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43291.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 208421390 is about 14436.8067798942. The cubic root of 208421390 is about 592.8990611618.

The spelling of 208421390 in words is "two hundred eight million, four hundred twenty-one thousand, three hundred ninety".