1021642857449 has 2 divisors, whose sum is σ = 1021642857450. Its totient is φ = 1021642857448.

The previous prime is 1021642857413. The next prime is 1021642857497. The reversal of 1021642857449 is 9447582461201.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 995668700224 + 25974157225 = 997832^2 + 161165^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1021642857449 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1021642857449.

It is not a weakly prime, because it can be changed into another prime (1021642857749) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510821428724 + 510821428725.

It is an arithmetic number, because the mean of its divisors is an integer number (510821428725).

Almost surely, 2^{1021642857449} is an apocalyptic number.

It is an amenable number.

1021642857449 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021642857449 is an equidigital number, since it uses as much as digits as its factorization.

1021642857449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3870720, while the sum is 53.

The spelling of 1021642857449 in words is "one trillion, twenty-one billion, six hundred forty-two million, eight hundred fifty-seven thousand, four hundred forty-nine".