102021649 has 2 divisors, whose sum is σ = 102021650. Its totient is φ = 102021648.

The previous prime is 102021643. The next prime is 102021677. The reversal of 102021649 is 946120201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 100641024 + 1380625 = 10032^2 + 1175^2 .

It is a cyclic number.

It is not a de Polignac number, because 102021649 - 2¹⁵ = 101988881 is a prime.

It is not a weakly prime, because it can be changed into another prime (102021643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51010824 + 51010825.

It is an arithmetic number, because the mean of its divisors is an integer number (51010825).

Almost surely, 2^102021649 is an apocalyptic number.

It is an amenable number.

102021649 is a deficient number, since it is larger than the sum of its proper divisors (1).

102021649 is an equidigital number, since it uses as much as digits as its factorization.

102021649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 102021649 is about 10100.5766667057. The cubic root of 102021649 is about 467.2659264594.

The spelling of 102021649 in words is "one hundred two million, twenty-one thousand, six hundred forty-nine".