1286402021 has 2 divisors, whose sum is σ = 1286402022. Its totient is φ = 1286402020.

The previous prime is 1286402003. The next prime is 1286402059. The reversal of 1286402021 is 1202046821.

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., 923308996 + 363093025 = 30386^2 + 19055^2 .

It is a cyclic number.

It is not a de Polignac number, because 1286402021 - 2³⁰ = 212660197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1286422021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643201010 + 643201011.

It is an arithmetic number, because the mean of its divisors is an integer number (643201011).

Almost surely, 2^1286402021 is an apocalyptic number.

It is an amenable number.

1286402021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1286402021 is an equidigital number, since it uses as much as digits as its factorization.

1286402021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 1286402021 is about 35866.4470083113. The cubic root of 1286402021 is about 1087.5742202571.

Adding to 1286402021 its reverse (1202046821), we get a palindrome (2488448842).

The spelling of 1286402021 in words is "one billion, two hundred eighty-six million, four hundred two thousand, twenty-one".