781161812 has 12 divisors (see below), whose sum is σ = 1370298720. Its totient is φ = 389647896.

The previous prime is 781161803. The next prime is 781161817. The reversal of 781161812 is 218161187.

It is a super-2 number, since 2×781161812² = 1220427553054246688, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (781161817) 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, 231368 + ... + 234719.

It is an arithmetic number, because the mean of its divisors is an integer number (114191560).

Almost surely, 2^781161812 is an apocalyptic number.

It is an amenable number.

781161812 is a deficient number, since it is larger than the sum of its proper divisors (589136908).

781161812 is a wasteful number, since it uses less digits than its factorization.

781161812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466510 (or 466508 counting only the distinct ones).

The product of its digits is 5376, while the sum is 35.

The square root of 781161812 is about 27949.2721193236. The cubic root of 781161812 is about 920.9732187033.

The spelling of 781161812 in words is "seven hundred eighty-one million, one hundred sixty-one thousand, eight hundred twelve".