1209691643 has 2 divisors, whose sum is σ = 1209691644. Its totient is φ = 1209691642.

The previous prime is 1209691619. The next prime is 1209691657. The reversal of 1209691643 is 3461969021.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1209691643 - 2¹⁰ = 1209690619 is a prime.

It is a super-2 number, since 2×1209691643² = 2926707742288078898, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1209691643.

It is not a weakly prime, because it can be changed into another prime (1209696643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 604845821 + 604845822.

It is an arithmetic number, because the mean of its divisors is an integer number (604845822).

Almost surely, 2^1209691643 is an apocalyptic number.

1209691643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1209691643 is an equidigital number, since it uses as much as digits as its factorization.

1209691643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 1209691643 is about 34780.6216591941. The cubic root of 1209691643 is about 1065.5117095420.

The spelling of 1209691643 in words is "one billion, two hundred nine million, six hundred ninety-one thousand, six hundred forty-three".