20131002221 has 4 divisors (see below), whose sum is σ = 21961093344. Its totient is φ = 18300911100.

The previous prime is 20131002197. The next prime is 20131002233. The reversal of 20131002221 is 12220013102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20131002221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20131002196 and 20131002205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20134002221) 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, 915045545 + ... + 915045566.

It is an arithmetic number, because the mean of its divisors is an integer number (5490273336).

Almost surely, 2^20131002221 is an apocalyptic number.

It is an amenable number.

20131002221 is a deficient number, since it is larger than the sum of its proper divisors (1830091123).

20131002221 is a wasteful number, since it uses less digits than its factorization.

20131002221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1830091122.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 20131002221 its reverse (12220013102), we get a palindrome (32351015323).

The spelling of 20131002221 in words is "twenty billion, one hundred thirty-one million, two thousand, two hundred twenty-one".