1816662587261 has 16 divisors (see below), whose sum is σ = 1936379136384. Its totient is φ = 1698385688064.

The previous prime is 1816662587251. The next prime is 1816662587381. The reversal of 1816662587261 is 1627852666181.

It is a cyclic number.

It is not a de Polignac number, because 1816662587261 - 2⁶ = 1816662587197 is a prime.

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 1816662587261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1816662587251) 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, 4940561 + ... + 5295513.

It is an arithmetic number, because the mean of its divisors is an integer number (121023696024).

Almost surely, 2^{1816662587261} is an apocalyptic number.

It is an amenable number.

1816662587261 is a deficient number, since it is larger than the sum of its proper divisors (119716549123).

1816662587261 is a wasteful number, since it uses less digits than its factorization.

1816662587261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356980.

The product of its digits is 11612160, while the sum is 59.

The spelling of 1816662587261 in words is "one trillion, eight hundred sixteen billion, six hundred sixty-two million, five hundred eighty-seven thousand, two hundred sixty-one".