2018661273616 has 135 divisors (see below), whose sum is σ = 4297275528471. Its totient is φ = 918220672512.

The previous prime is 2018661273599. The next prime is 2018661273623. The reversal of 2018661273616 is 6163721668102.

The square root of 2018661273616 is 1420796.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 882509936400 + 1136151337216 = 939420^2 + 1065904^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2018661273616.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 6575443735 + ... + 6575444041.

Almost surely, 2^{2018661273616} is an apocalyptic number.

2018661273616 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

2018661273616 is the 1420796-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2018661273616

2018661273616 is an abundant number, since it is smaller than the sum of its proper divisors (2278614254855).

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

2018661273616 is an frugal number, since it uses more digits than its factorization.

2018661273616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826 (or 411 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 49.

Multiplying 2018661273616 by its sum of digits (49), we get a square (98914402407184 = 9945572²).

The spelling of 2018661273616 in words is "two trillion, eighteen billion, six hundred sixty-one million, two hundred seventy-three thousand, six hundred sixteen".