818211605 has 16 divisors (see below), whose sum is σ = 1007868528. Its totient is φ = 637440000.

The previous prime is 818211533. The next prime is 818211677. The reversal of 818211605 is 506112818.

It is an interprime number because it is at equal distance from previous prime (818211533) and next prime (818211677).

It can be written as a sum of positive squares in 8 ways, for example, as 11992369 + 806219236 = 3463^2 + 28394^2 .

It is not a de Polignac number, because 818211605 - 2⁸ = 818211349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17525 + ... + 44085.

It is an arithmetic number, because the mean of its divisors is an integer number (62991783).

Almost surely, 2^818211605 is an apocalyptic number.

It is an amenable number.

818211605 is a deficient number, since it is larger than the sum of its proper divisors (189656923).

818211605 is a wasteful number, since it uses less digits than its factorization.

818211605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26728.

The product of its (nonzero) digits is 3840, while the sum is 32.

The square root of 818211605 is about 28604.3983506034. The cubic root of 818211605 is about 935.3092116938.

The spelling of 818211605 in words is "eight hundred eighteen million, two hundred eleven thousand, six hundred five".