802217821 has 2 divisors, whose sum is σ = 802217822. Its totient is φ = 802217820.

The previous prime is 802217809. The next prime is 802217827. The reversal of 802217821 is 128712208.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 453051225 + 349166596 = 21285^2 + 18686^2 .

It is a cyclic number.

It is not a de Polignac number, because 802217821 - 2⁷ = 802217693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (802217827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 401108910 + 401108911.

It is an arithmetic number, because the mean of its divisors is an integer number (401108911).

Almost surely, 2^802217821 is an apocalyptic number.

It is an amenable number.

802217821 is a deficient number, since it is larger than the sum of its proper divisors (1).

802217821 is an equidigital number, since it uses as much as digits as its factorization.

802217821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 802217821 is about 28323.4500193744. The cubic root of 802217821 is about 929.1748263069.

The spelling of 802217821 in words is "eight hundred two million, two hundred seventeen thousand, eight hundred twenty-one".