18161666425890 has 768 divisors, whose sum is σ = 59411722406400. Its totient is φ = 3920596992000.

The previous prime is 18161666425823. The next prime is 18161666425957. The reversal of 18161666425890 is 9852466616181.

It is an interprime number because it is at equal distance from previous prime (18161666425823) and next prime (18161666425957).

It is a super-2 number, since 2×18161666425890² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 899037790 + ... + 899057990.

It is an arithmetic number, because the mean of its divisors is an integer number (77359013550).

Almost surely, 2^{18161666425890} is an apocalyptic number.

18161666425890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18161666425890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29705861203200).

18161666425890 is an abundant number, since it is smaller than the sum of its proper divisors (41250055980510).

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

18161666425890 is a wasteful number, since it uses less digits than its factorization.

18161666425890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20340 (or 20321 counting only the distinct ones).

The product of its (nonzero) digits is 29859840, while the sum is 63.

The spelling of 18161666425890 in words is "eighteen trillion, one hundred sixty-one billion, six hundred sixty-six million, four hundred twenty-five thousand, eight hundred ninety".