1662536021 has 2 divisors, whose sum is σ = 1662536022. Its totient is φ = 1662536020.

The previous prime is 1662536009. The next prime is 1662536087. The reversal of 1662536021 is 1206352661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1657629796 + 4906225 = 40714^2 + 2215^2 .

It is an emirp because it is prime and its reverse (1206352661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1662536021 - 2¹⁴ = 1662519637 is a prime.

It is a super-2 number, since 2×1662536021² = 5528052042245024882, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1662536221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831268010 + 831268011.

It is an arithmetic number, because the mean of its divisors is an integer number (831268011).

Almost surely, 2^1662536021 is an apocalyptic number.

It is an amenable number.

1662536021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1662536021 is an equidigital number, since it uses as much as digits as its factorization.

1662536021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 1662536021 is about 40774.2077912006. The cubic root of 1662536021 is about 1184.6508068058.

Adding to 1662536021 its reverse (1206352661), we get a palindrome (2868888682).

The spelling of 1662536021 in words is "one billion, six hundred sixty-two million, five hundred thirty-six thousand, twenty-one".