18862821 has 16 divisors (see below), whose sum is σ = 28163520. Its totient is φ = 12476880.

The previous prime is 18862819. The next prime is 18862871. The reversal of 18862821 is 12826881.

18862821 is a `hidden beast` number, since 1 + 8 + 8 + 628 + 21 = 666.

It is not a de Polignac number, because 18862821 - 2¹ = 18862819 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18862871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 871 + ... + 6203.

It is an arithmetic number, because the mean of its divisors is an integer number (1760220).

Almost surely, 2^18862821 is an apocalyptic number.

It is an amenable number.

18862821 is a deficient number, since it is larger than the sum of its proper divisors (9300699).

18862821 is a wasteful number, since it uses less digits than its factorization.

18862821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5473 (or 5467 counting only the distinct ones).

The product of its digits is 12288, while the sum is 36.

The square root of 18862821 is about 4343.1349276761. The cubic root of 18862821 is about 266.1964224667.

It can be divided in two parts, 18862 and 821, that added together give a 9-th power (19683 = 3⁹).

The spelling of 18862821 in words is "eighteen million, eight hundred sixty-two thousand, eight hundred twenty-one".