201978500 has 24 divisors (see below), whose sum is σ = 441122136. Its totient is φ = 80791200.

The previous prime is 201978473. The next prime is 201978509. The reversal of 201978500 is 5879102.

It can be written as a sum of positive squares in 4 ways, for example, as 48664576 + 153313924 = 6976^2 + 12382^2 .

It is not an unprimeable number, because it can be changed into a prime (201978509) by changing a digit.

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, 201479 + ... + 202478.

It is an arithmetic number, because the mean of its divisors is an integer number (18380089).

Almost surely, 2^201978500 is an apocalyptic number.

201978500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201978500 is an abundant number, since it is smaller than the sum of its proper divisors (239143636).

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

201978500 is a wasteful number, since it uses less digits than its factorization.

201978500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403976 (or 403964 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 201978500 is about 14211.9140160641. The cubic root of 201978500 is about 586.7256131943.

The spelling of 201978500 in words is "two hundred one million, nine hundred seventy-eight thousand, five hundred".