18212890625 has 24 divisors (see below), whose sum is σ = 22827148344. Its totient is φ = 14531250000.

The previous prime is 18212890621. The next prime is 18212890627. The reversal of 18212890625 is 52609821281.

It can be written as a sum of positive squares in 12 ways, for example, as 8619079921 + 9593810704 = 92839^2 + 97948^2 .

It is an automorphic number since its square, 331709384918212890625, ends in 18212890625.

It is a trimorphic number since its cube, 6041386746801435947418212890625, ends in 18212890625.

It is not a de Polignac number, because 18212890625 - 2² = 18212890621 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18212890621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48827939 + ... + 48828311.

It is an arithmetic number, because the mean of its divisors is an integer number (951131181).

Almost surely, 2^18212890625 is an apocalyptic number.

It is an amenable number.

18212890625 is a deficient number, since it is larger than the sum of its proper divisors (4614257719).

18212890625 is an frugal number, since it uses more digits than its factorization.

18212890625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 44.

The spelling of 18212890625 in words is "eighteen billion, two hundred twelve million, eight hundred ninety thousand, six hundred twenty-five".