21121221199 has 16 divisors (see below), whose sum is σ = 23957056480. Its totient is φ = 18459601920.

The previous prime is 21121221193. The next prime is 21121221221. The reversal of 21121221199 is 99112212112.

It is a cyclic number.

It is not a de Polignac number, because 21121221199 - 2¹¹ = 21121219151 is a prime.

It is a super-2 number, since 2×21121221199² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21121221199.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121221193) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 414859 + ... + 462979.

It is an arithmetic number, because the mean of its divisors is an integer number (1497316030).

Almost surely, 2^21121221199 is an apocalyptic number.

21121221199 is a deficient number, since it is larger than the sum of its proper divisors (2835835281).

21121221199 is a wasteful number, since it uses less digits than its factorization.

21121221199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49930.

The product of its digits is 1296, while the sum is 31.

The spelling of 21121221199 in words is "twenty-one billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred ninety-nine".