21121001983 has 4 divisors (see below), whose sum is σ = 21193087608. Its totient is φ = 21048916360.

The previous prime is 21121001969. The next prime is 21121002029. The reversal of 21121001983 is 38910012112.

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

It is a cyclic number.

It is not a de Polignac number, because 21121001983 - 2¹³ = 21120993791 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121001183) by changing a digit.

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, 36042373 + ... + 36042958.

It is an arithmetic number, because the mean of its divisors is an integer number (5298271902).

Almost surely, 2^21121001983 is an apocalyptic number.

21121001983 is a deficient number, since it is larger than the sum of its proper divisors (72085625).

21121001983 is an equidigital number, since it uses as much as digits as its factorization.

21121001983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72085624.

The product of its (nonzero) digits is 864, while the sum is 28.

The spelling of 21121001983 in words is "twenty-one billion, one hundred twenty-one million, one thousand, nine hundred eighty-three".