645543029 has 2 divisors, whose sum is σ = 645543030. Its totient is φ = 645543028.

The previous prime is 645542999. The next prime is 645543071. The reversal of 645543029 is 920345546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 575904004 + 69639025 = 23998^2 + 8345^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-645543029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 645542983 and 645543001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645543089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322771514 + 322771515.

It is an arithmetic number, because the mean of its divisors is an integer number (322771515).

Almost surely, 2^645543029 is an apocalyptic number.

It is an amenable number.

645543029 is a deficient number, since it is larger than the sum of its proper divisors (1).

645543029 is an equidigital number, since it uses as much as digits as its factorization.

645543029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129600, while the sum is 38.

The square root of 645543029 is about 25407.5388221685. The cubic root of 645543029 is about 864.2546639601.

The spelling of 645543029 in words is "six hundred forty-five million, five hundred forty-three thousand, twenty-nine".