821290663 has 2 divisors, whose sum is σ = 821290664. Its totient is φ = 821290662.

The previous prime is 821290619. The next prime is 821290681. The reversal of 821290663 is 366092128.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 821290663 - 2¹³ = 821282471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (821290363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410645331 + 410645332.

It is an arithmetic number, because the mean of its divisors is an integer number (410645332).

Almost surely, 2^821290663 is an apocalyptic number.

821290663 is a deficient number, since it is larger than the sum of its proper divisors (1).

821290663 is an equidigital number, since it uses as much as digits as its factorization.

821290663 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 821290663 is about 28658.1692192645. The cubic root of 821290663 is about 936.4809812614.

The spelling of 821290663 in words is "eight hundred twenty-one million, two hundred ninety thousand, six hundred sixty-three".