213797221101985 has 4 divisors (see below), whose sum is σ = 256556665322388. Its totient is φ = 171037776881584.

The previous prime is 213797221101977. The next prime is 213797221101991. The reversal of 213797221101985 is 589101122797312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 78376334947681 + 135420886154304 = 8853041^2 + 11637048^2 .

It is a cyclic number.

It is not a de Polignac number, because 213797221101985 - 2³ = 213797221101977 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21379722110194 + ... + 21379722110203.

It is an arithmetic number, because the mean of its divisors is an integer number (64139166330597).

Almost surely, 2^{213797221101985} is an apocalyptic number.

It is an amenable number.

213797221101985 is a deficient number, since it is larger than the sum of its proper divisors (42759444220403).

213797221101985 is an equidigital number, since it uses as much as digits as its factorization.

213797221101985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42759444220402.

The product of its (nonzero) digits is 3810240, while the sum is 58.

The spelling of 213797221101985 in words is "two hundred thirteen trillion, seven hundred ninety-seven billion, two hundred twenty-one million, one hundred one thousand, nine hundred eighty-five".