821964043 has 2 divisors, whose sum is σ = 821964044. Its totient is φ = 821964042.

The previous prime is 821964029. The next prime is 821964047. The reversal of 821964043 is 340469128.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-821964043 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 821963993 and 821964011.

It is not a weakly prime, because it can be changed into another prime (821964047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410982021 + 410982022.

It is an arithmetic number, because the mean of its divisors is an integer number (410982022).

Almost surely, 2^821964043 is an apocalyptic number.

821964043 is a deficient number, since it is larger than the sum of its proper divisors (1).

821964043 is an equidigital number, since it uses as much as digits as its factorization.

821964043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 821964043 is about 28669.9152946080. The cubic root of 821964043 is about 936.7368530350.

The spelling of 821964043 in words is "eight hundred twenty-one million, nine hundred sixty-four thousand, forty-three".