819212993 has 4 divisors (see below), whose sum is σ = 819675780. Its totient is φ = 818750208.

The previous prime is 819212959. The next prime is 819213001. The reversal of 819212993 is 399212918.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 288048784 + 531164209 = 16972^2 + 23047^2 .

It is a cyclic number.

It is not a de Polignac number, because 819212993 - 2⁶ = 819212929 is a prime.

It is a super-2 number, since 2×819212993² = 1342219855800036098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (819212903) 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, 228728 + ... + 232281.

It is an arithmetic number, because the mean of its divisors is an integer number (204918945).

Almost surely, 2^819212993 is an apocalyptic number.

It is an amenable number.

819212993 is a deficient number, since it is larger than the sum of its proper divisors (462787).

819212993 is a wasteful number, since it uses less digits than its factorization.

819212993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462786.

The product of its digits is 69984, while the sum is 44.

The square root of 819212993 is about 28621.8970894663. The cubic root of 819212993 is about 935.6906230460.

The spelling of 819212993 in words is "eight hundred nineteen million, two hundred twelve thousand, nine hundred ninety-three".