1091643569 has 2 divisors, whose sum is σ = 1091643570. Its totient is φ = 1091643568.

The previous prime is 1091643551. The next prime is 1091643577. The reversal of 1091643569 is 9653461901.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 941262400 + 150381169 = 30680^2 + 12263^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1091643569 is a prime.

It is a super-2 number, since 2×1091643569² = 2383371363478115522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1091643599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545821784 + 545821785.

It is an arithmetic number, because the mean of its divisors is an integer number (545821785).

Almost surely, 2^1091643569 is an apocalyptic number.

It is an amenable number.

1091643569 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091643569 is an equidigital number, since it uses as much as digits as its factorization.

1091643569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 174960, while the sum is 44.

The square root of 1091643569 is about 33040.0297972021. The cubic root of 1091643569 is about 1029.6594748896.

The spelling of 1091643569 in words is "one billion, ninety-one million, six hundred forty-three thousand, five hundred sixty-nine".