210505455640 has 32 divisors (see below), whose sum is σ = 476017380000. Its totient is φ = 83779052544.

The previous prime is 210505455617. The next prime is 210505455673. The reversal of 210505455640 is 46554505012.

It is a self number, because there is not a number n which added to its sum of digits gives 210505455640.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13214745 + ... + 13230664.

It is an arithmetic number, because the mean of its divisors is an integer number (14875543125).

Almost surely, 2^210505455640 is an apocalyptic number.

210505455640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

210505455640 is an abundant number, since it is smaller than the sum of its proper divisors (265511924360).

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

210505455640 is a wasteful number, since it uses less digits than its factorization.

210505455640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26445619 (or 26445615 counting only the distinct ones).

The product of its (nonzero) digits is 120000, while the sum is 37.

The spelling of 210505455640 in words is "two hundred ten billion, five hundred five million, four hundred fifty-five thousand, six hundred forty".