2149311821 has 2 divisors, whose sum is σ = 2149311822. Its totient is φ = 2149311820.

The previous prime is 2149311811. The next prime is 2149311839. The reversal of 2149311821 is 1281139412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1168682596 + 980629225 = 34186^2 + 31315^2 .

It is a cyclic number.

It is not a de Polignac number, because 2149311821 - 2⁶ = 2149311757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2149311811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1074655910 + 1074655911.

It is an arithmetic number, because the mean of its divisors is an integer number (1074655911).

Almost surely, 2^2149311821 is an apocalyptic number.

It is an amenable number.

2149311821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2149311821 is an equidigital number, since it uses as much as digits as its factorization.

2149311821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 32.

The square root of 2149311821 is about 46360.6710585600. The cubic root of 2149311821 is about 1290.5251594532.

The spelling of 2149311821 in words is "two billion, one hundred forty-nine million, three hundred eleven thousand, eight hundred twenty-one".