102730021 has 2 divisors, whose sum is σ = 102730022. Its totient is φ = 102730020.

The previous prime is 102730009. The next prime is 102730027. The reversal of 102730021 is 120037201.

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., 95277121 + 7452900 = 9761^2 + 2730^2 .

It is a cyclic number.

It is not a de Polignac number, because 102730021 - 2⁹ = 102729509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 102729977 and 102730004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102730027) 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, 51365010 + 51365011.

It is an arithmetic number, because the mean of its divisors is an integer number (51365011).

Almost surely, 2^102730021 is an apocalyptic number.

It is an amenable number.

102730021 is a deficient number, since it is larger than the sum of its proper divisors (1).

102730021 is an equidigital number, since it uses as much as digits as its factorization.

102730021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 102730021 is about 10135.5819270528. The cubic root of 102730021 is about 468.3448966749.

Adding to 102730021 its reverse (120037201), we get a palindrome (222767222).

The spelling of 102730021 in words is "one hundred two million, seven hundred thirty thousand, twenty-one".