823144991 has 2 divisors, whose sum is σ = 823144992. Its totient is φ = 823144990.

The previous prime is 823144969. The next prime is 823145009. The reversal of 823144991 is 199441328.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 823144991 - 2¹⁸ = 822882847 is a prime.

It is a super-3 number, since 3×823144991³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (823144921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411572495 + 411572496.

It is an arithmetic number, because the mean of its divisors is an integer number (411572496).

Almost surely, 2^823144991 is an apocalyptic number.

823144991 is a deficient number, since it is larger than the sum of its proper divisors (1).

823144991 is an equidigital number, since it uses as much as digits as its factorization.

823144991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 41.

The square root of 823144991 is about 28690.5034985446. The cubic root of 823144991 is about 937.1852538920.

The spelling of 823144991 in words is "eight hundred twenty-three million, one hundred forty-four thousand, nine hundred ninety-one".