1081291690 has 16 divisors (see below), whose sum is σ = 1983049128. Its totient is φ = 424355776.

The previous prime is 1081291667. The next prime is 1081291711. The reversal of 1081291690 is 961921801.

It is a Cunningham number, because it is equal to 32883²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 1081291689 + 1 = 32883^2 + 1^2 .

It is a super-2 number, since 2×1081291690² = 2338383437726112200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1019557 + ... + 1020616.

Almost surely, 2^1081291690 is an apocalyptic number.

1081291690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1081291690 is a deficient number, since it is larger than the sum of its proper divisors (901757438).

1081291690 is a wasteful number, since it uses less digits than its factorization.

1081291690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2040233.

The product of its (nonzero) digits is 7776, while the sum is 37.

The square root of 1081291690 is about 32883.0000152054. Note that the first 4 decimals coincide. The cubic root of 1081291690 is about 1026.3944344597.

The spelling of 1081291690 in words is "one billion, eighty-one million, two hundred ninety-one thousand, six hundred ninety".