211221001994 has 4 divisors (see below), whose sum is σ = 316831502994. Its totient is φ = 105610500996.

The previous prime is 211221001993. The next prime is 211221002039. The reversal of 211221001994 is 499100122112.

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

It can be written as a sum of positive squares in only one way, i.e., 211043766025 + 177235969 = 459395^2 + 13313^2 .

It is a super-2 number, since 2×211221001994² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 211221001994.

It is not an unprimeable number, because it can be changed into a prime (211221001993) by changing a digit.

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 as a sum of consecutive naturals, namely, 52805250497 + ... + 52805250500.

Almost surely, 2^211221001994 is an apocalyptic number.

211221001994 is a deficient number, since it is larger than the sum of its proper divisors (105610501000).

211221001994 is a wasteful number, since it uses less digits than its factorization.

211221001994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105610500999.

The product of its (nonzero) digits is 2592, while the sum is 32.

The spelling of 211221001994 in words is "two hundred eleven billion, two hundred twenty-one million, one thousand, nine hundred ninety-four".