1056561091 has 2 divisors, whose sum is σ = 1056561092. Its totient is φ = 1056561090.

The previous prime is 1056561083. The next prime is 1056561109. The reversal of 1056561091 is 1901656501.

Together with next prime (1056561109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1056561091 - 2³ = 1056561083 is a prime.

It is a super-2 number, since 2×1056561091² = 2232642678030220562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1056561061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 528280545 + 528280546.

It is an arithmetic number, because the mean of its divisors is an integer number (528280546).

Almost surely, 2^1056561091 is an apocalyptic number.

1056561091 is a deficient number, since it is larger than the sum of its proper divisors (1).

1056561091 is an equidigital number, since it uses as much as digits as its factorization.

1056561091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 1056561091 is about 32504.7856630374. The cubic root of 1056561091 is about 1018.5090002849.

The spelling of 1056561091 in words is "one billion, fifty-six million, five hundred sixty-one thousand, ninety-one".