18821040485781 has 72 divisors (see below), whose sum is σ = 27380013689952. Its totient is φ = 11498021668800.

The previous prime is 18821040485773. The next prime is 18821040485789. The reversal of 18821040485781 is 18758404012881.

It is an interprime number because it is at equal distance from previous prime (18821040485773) and next prime (18821040485789).

It is not a de Polignac number, because 18821040485781 - 2³ = 18821040485773 is a prime.

It is a super-2 number, since 2×18821040485781² (a number of 27 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18821040485789) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3685339230 + ... + 3685344336.

It is an arithmetic number, because the mean of its divisors is an integer number (380277967916).

Almost surely, 2^{18821040485781} is an apocalyptic number.

It is an amenable number.

18821040485781 is a deficient number, since it is larger than the sum of its proper divisors (8558973204171).

18821040485781 is a wasteful number, since it uses less digits than its factorization.

18821040485781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8751 (or 8701 counting only the distinct ones).

The product of its (nonzero) digits is 4587520, while the sum is 57.

The spelling of 18821040485781 in words is "eighteen trillion, eight hundred twenty-one billion, forty million, four hundred eighty-five thousand, seven hundred eighty-one".