2131220021 has 8 divisors (see below), whose sum is σ = 2440944384. Its totient is φ = 1822811760.

The previous prime is 2131220009. The next prime is 2131220041. The reversal of 2131220021 is 1200221312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2131220021 - 2¹⁰ = 2131218997 is a prime.

It is a super-2 number, since 2×2131220021² = 9084197555822480882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2131219978 and 2131220005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2131220041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 325550 + ... + 332031.

It is an arithmetic number, because the mean of its divisors is an integer number (305118048).

Almost surely, 2^2131220021 is an apocalyptic number.

It is an amenable number.

2131220021 is a deficient number, since it is larger than the sum of its proper divisors (309724363).

2131220021 is an equidigital number, since it uses as much as digits as its factorization.

2131220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658051.

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

The square root of 2131220021 is about 46165.1385896328. The cubic root of 2131220021 is about 1286.8939597368.

Adding to 2131220021 its reverse (1200221312), we get a palindrome (3331441333).

The spelling of 2131220021 in words is "two billion, one hundred thirty-one million, two hundred twenty thousand, twenty-one".