164654538721 has 2 divisors, whose sum is σ = 164654538722. Its totient is φ = 164654538720.

The previous prime is 164654538691. The next prime is 164654538731. The reversal of 164654538721 is 127835456461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120243191121 + 44411347600 = 346761^2 + 210740^2 .

It is a cyclic number.

It is not a de Polignac number, because 164654538721 - 2¹⁹ = 164654014433 is a prime.

It is a super-2 number, since 2×164654538721² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (164654538731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82327269360 + 82327269361.

It is an arithmetic number, because the mean of its divisors is an integer number (82327269361).

Almost surely, 2^164654538721 is an apocalyptic number.

It is an amenable number.

164654538721 is a deficient number, since it is larger than the sum of its proper divisors (1).

164654538721 is an equidigital number, since it uses as much as digits as its factorization.

164654538721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4838400, while the sum is 52.

The spelling of 164654538721 in words is "one hundred sixty-four billion, six hundred fifty-four million, five hundred thirty-eight thousand, seven hundred twenty-one".