1081555669 has 4 divisors (see below), whose sum is σ = 1081829196. Its totient is φ = 1081282144.

The previous prime is 1081555633. The next prime is 1081555729. The reversal of 1081555669 is 9665551801.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9665551801 = 137 ⋅70551473.

It can be written as a sum of positive squares in 2 ways, for example, as 906311025 + 175244644 = 30105^2 + 13238^2 .

It is a cyclic number.

It is not a de Polignac number, because 1081555669 - 2¹³ = 1081547477 is a prime.

It is a super-2 number, since 2×1081555669² = 2339525330292075122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1081555619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 130744 + ... + 138769.

It is an arithmetic number, because the mean of its divisors is an integer number (270457299).

Almost surely, 2^1081555669 is an apocalyptic number.

It is an amenable number.

1081555669 is a deficient number, since it is larger than the sum of its proper divisors (273527).

1081555669 is an equidigital number, since it uses as much as digits as its factorization.

1081555669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273526.

The product of its (nonzero) digits is 324000, while the sum is 46.

The square root of 1081555669 is about 32887.0136832154. The cubic root of 1081555669 is about 1026.4779532527.

The spelling of 1081555669 in words is "one billion, eighty-one million, five hundred fifty-five thousand, six hundred sixty-nine".