1021640129 has 2 divisors, whose sum is σ = 1021640130. Its totient is φ = 1021640128.

The previous prime is 1021640117. The next prime is 1021640141. The reversal of 1021640129 is 9210461201.

It is a balanced prime because it is at equal distance from previous prime (1021640117) and next prime (1021640141).

It can be written as a sum of positive squares in only one way, i.e., 607721104 + 413919025 = 24652^2 + 20345^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021640129 - 2²⁰ = 1020591553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021640098 and 1021640107.

It is not a weakly prime, because it can be changed into another prime (1021640429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510820064 + 510820065.

It is an arithmetic number, because the mean of its divisors is an integer number (510820065).

Almost surely, 2^1021640129 is an apocalyptic number.

It is an amenable number.

1021640129 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021640129 is an equidigital number, since it uses as much as digits as its factorization.

1021640129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 1021640129 is about 31963.1057470954. The cubic root of 1021640129 is about 1007.1619602049.

The spelling of 1021640129 in words is "one billion, twenty-one million, six hundred forty thousand, one hundred twenty-nine".