812911381 has 8 divisors (see below), whose sum is σ = 827940960. Its totient is φ = 797923632.

The previous prime is 812911361. The next prime is 812911397. The reversal of 812911381 is 183119218.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 812911381 - 2²¹ = 810814229 is a prime.

It is a super-2 number, since 2×812911381² = 1321649826718654322, 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 (812911301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30211 + ... + 50383.

It is an arithmetic number, because the mean of its divisors is an integer number (103492620).

Almost surely, 2^812911381 is an apocalyptic number.

It is an amenable number.

812911381 is a deficient number, since it is larger than the sum of its proper divisors (15029579).

812911381 is a wasteful number, since it uses less digits than its factorization.

812911381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20915.

The product of its digits is 3456, while the sum is 34.

The square root of 812911381 is about 28511.6008144054. The cubic root of 812911381 is about 933.2852481888.

The spelling of 812911381 in words is "eight hundred twelve million, nine hundred eleven thousand, three hundred eighty-one".