18309298644 has 252 divisors, whose sum is σ = 60187999284. Its totient is φ = 4828336128.

The previous prime is 18309298613. The next prime is 18309298691. The reversal of 18309298644 is 44689290381.

18309298644 is a `hidden beast` number, since 1 + 8 + 309 + 298 + 6 + 44 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 4578146244 + 13731152400 = 67662^2 + 117180^2 .

It is a tau number, because it is divible by the number of its divisors (252).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 1852564 + ... + 1862420.

It is an arithmetic number, because the mean of its divisors is an integer number (238841267).

Almost surely, 2^18309298644 is an apocalyptic number.

18309298644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18309298644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30093999642).

18309298644 is an abundant number, since it is smaller than the sum of its proper divisors (41878700640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18309298644 is a wasteful number, since it uses less digits than its factorization.

18309298644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9906 (or 9882 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The spelling of 18309298644 in words is "eighteen billion, three hundred nine million, two hundred ninety-eight thousand, six hundred forty-four".