1290891101 has 2 divisors, whose sum is σ = 1290891102. Its totient is φ = 1290891100.

The previous prime is 1290891083. The next prime is 1290891127. The reversal of 1290891101 is 1011980921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 702780100 + 588111001 = 26510^2 + 24251^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1290891101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1290891001) 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, 645445550 + 645445551.

It is an arithmetic number, because the mean of its divisors is an integer number (645445551).

Almost surely, 2^1290891101 is an apocalyptic number.

It is an amenable number.

1290891101 is a deficient number, since it is larger than the sum of its proper divisors (1).

1290891101 is an equidigital number, since it uses as much as digits as its factorization.

1290891101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 32.

The square root of 1290891101 is about 35928.9730023000. The cubic root of 1290891101 is about 1088.8378323929.

The spelling of 1290891101 in words is "one billion, two hundred ninety million, eight hundred ninety-one thousand, one hundred one".