2164252021 has 2 divisors, whose sum is σ = 2164252022. Its totient is φ = 2164252020.

The previous prime is 2164251967. The next prime is 2164252037. The reversal of 2164252021 is 1202524612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1830641796 + 333610225 = 42786^2 + 18265^2 .

It is a cyclic number.

It is not a de Polignac number, because 2164252021 - 2¹¹ = 2164249973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2164252061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1082126010 + 1082126011.

It is an arithmetic number, because the mean of its divisors is an integer number (1082126011).

Almost surely, 2^2164252021 is an apocalyptic number.

It is an amenable number.

2164252021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2164252021 is an equidigital number, since it uses as much as digits as its factorization.

2164252021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 2164252021 is about 46521.5221268608. The cubic root of 2164252021 is about 1293.5084711559.

Adding to 2164252021 its reverse (1202524612), we get a palindrome (3366776633).

The spelling of 2164252021 in words is "two billion, one hundred sixty-four million, two hundred fifty-two thousand, twenty-one".