3712781781 has 6 divisors (see below), whose sum is σ = 5362907030. Its totient is φ = 2475187848.

The previous prime is 3712781767. The next prime is 3712781801. The reversal of 3712781781 is 1871872173.

It is a happy number.

3712781781 is a `hidden beast` number, since 371 + 278 + 1 + 7 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 3700775556 + 12006225 = 60834^2 + 3465^2 .

It is not a de Polignac number, because 3712781781 - 2⁹ = 3712781269 is a prime.

It is a super-2 number, since 2×3712781781² = 27569497106651063922, 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 (3712781711) 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, 206265646 + ... + 206265663.

Almost surely, 2^3712781781 is an apocalyptic number.

It is an amenable number.

3712781781 is a deficient number, since it is larger than the sum of its proper divisors (1650125249).

3712781781 is a wasteful number, since it uses less digits than its factorization.

3712781781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412531315 (or 412531312 counting only the distinct ones).

The product of its digits is 131712, while the sum is 45.

The square root of 3712781781 is about 60932.6003137893. The cubic root of 3712781781 is about 1548.4593475366.

The spelling of 3712781781 in words is "three billion, seven hundred twelve million, seven hundred eighty-one thousand, seven hundred eighty-one".