2131221373 has 2 divisors, whose sum is σ = 2131221374. Its totient is φ = 2131221372.

The previous prime is 2131221361. The next prime is 2131221383. The reversal of 2131221373 is 3731221312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1748745124 + 382476249 = 41818^2 + 19557^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2131221373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2131221383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1065610686 + 1065610687.

It is an arithmetic number, because the mean of its divisors is an integer number (1065610687).

Almost surely, 2^2131221373 is an apocalyptic number.

It is an amenable number.

2131221373 is a deficient number, since it is larger than the sum of its proper divisors (1).

2131221373 is an equidigital number, since it uses as much as digits as its factorization.

2131221373 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1512, while the sum is 25.

The square root of 2131221373 is about 46165.1532327144. The cubic root of 2131221373 is about 1286.8942318627.

Adding to 2131221373 its reverse (3731221312), we get a palindrome (5862442685).

The spelling of 2131221373 in words is "two billion, one hundred thirty-one million, two hundred twenty-one thousand, three hundred seventy-three".