72821663 has 2 divisors, whose sum is σ = 72821664. Its totient is φ = 72821662.

The previous prime is 72821621. The next prime is 72821677. The reversal of 72821663 is 36612827.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (36612827) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72821663 - 2⁶ = 72821599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72827663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36410831 + 36410832.

It is an arithmetic number, because the mean of its divisors is an integer number (36410832).

Almost surely, 2^72821663 is an apocalyptic number.

72821663 is a deficient number, since it is larger than the sum of its proper divisors (1).

72821663 is an equidigital number, since it uses as much as digits as its factorization.

72821663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 35.

The square root of 72821663 is about 8533.5609800364. The cubic root of 72821663 is about 417.5933084143.

The spelling of 72821663 in words is "seventy-two million, eight hundred twenty-one thousand, six hundred sixty-three".