811021906 has 32 divisors (see below), whose sum is σ = 1300147200. Its totient is φ = 378589200.

The previous prime is 811021903. The next prime is 811021909. The reversal of 811021906 is 609120118.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (811021903) and next prime (811021909).

It is not an unprimeable number, because it can be changed into a prime (811021903) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 408825 + ... + 410803.

It is an arithmetic number, because the mean of its divisors is an integer number (40629600).

Almost surely, 2^811021906 is an apocalyptic number.

811021906 is a deficient number, since it is larger than the sum of its proper divisors (489125294).

811021906 is a wasteful number, since it uses less digits than its factorization.

811021906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2214.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 811021906 is about 28478.4463410489. The cubic root of 811021906 is about 932.5615993348.

The spelling of 811021906 in words is "eight hundred eleven million, twenty-one thousand, nine hundred six".