1081683781 has 6 divisors (see below), whose sum is σ = 1099677446. Its totient is φ = 1063698600.

The previous prime is 1081683773. The next prime is 1081683787. The reversal of 1081683781 is 1873861801.

It can be written as a sum of positive squares in only one way, i.e., 638370756 + 443313025 = 25266^2 + 21055^2 .

It is not a de Polignac number, because 1081683781 - 2³ = 1081683773 is a prime.

It is a super-2 number, since 2×1081683781² = 2340079604156911922, 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 (1081683787) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 254766 + ... + 258976.

Almost surely, 2^1081683781 is an apocalyptic number.

It is an amenable number.

1081683781 is a deficient number, since it is larger than the sum of its proper divisors (17993665).

1081683781 is an frugal number, since it uses more digits than its factorization.

1081683781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8483 (or 4272 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 43.

The square root of 1081683781 is about 32888.9613852429. The cubic root of 1081683781 is about 1026.5184809713.

The spelling of 1081683781 in words is "one billion, eighty-one million, six hundred eighty-three thousand, seven hundred eighty-one".