811623121 has 9 divisors (see below), whose sum is σ = 839562633. Its totient is φ = 784587060.

The previous prime is 811623107. The next prime is 811623143. The reversal of 811623121 is 121326118.

The square root of 811623121 is 28489.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 811623121 - 2¹⁹ = 811098833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (811623221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 882700 + ... + 883618.

It is an arithmetic number, because the mean of its divisors is an integer number (93284737).

Almost surely, 2^811623121 is an apocalyptic number.

811623121 is the 28489-th square number.

811623121 is the 14245-th centered octagonal number.

It is an amenable number.

811623121 is a deficient number, since it is larger than the sum of its proper divisors (27939512).

811623121 is an frugal number, since it uses more digits than its factorization.

811623121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1900 (or 950 counting only the distinct ones).

The product of its digits is 576, while the sum is 25.

The cubic root of 811623121 is about 932.7919800977.

Multiplying 811623121 by its sum of digits (25), we get a square (20290578025 = 142445²).

Multiplying 811623121 by its product of digits (576), we get a square (467494917696 = 683736²).

Adding to 811623121 its reverse (121326118), we get a palindrome (932949239).

The spelling of 811623121 in words is "eight hundred eleven million, six hundred twenty-three thousand, one hundred twenty-one".