1618806481920 has 132 divisors (see below), whose sum is σ = 5609122463100. Its totient is φ = 431681716224.

The previous prime is 1618806481913. The next prime is 1618806481921. The reversal of 1618806481920 is 291846088161.

It is a happy number.

1618806481920 is a `hidden beast` number, since 1 + 61 + 8 + 80 + 6 + 481 + 9 + 20 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 261227298816 + 1357579183104 = 511104^2 + 1165152^2 .

It is not an unprimeable number, because it can be changed into a prime (1618806481921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17519095 + ... + 17611254.

Almost surely, 2^{1618806481920} is an apocalyptic number.

1618806481920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1618806481920 is an abundant number, since it is smaller than the sum of its proper divisors (3990315981180).

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

1618806481920 is a wasteful number, since it uses less digits than its factorization.

1618806481920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35130380 (or 35130359 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 54.

The spelling of 1618806481920 in words is "one trillion, six hundred eighteen billion, eight hundred six million, four hundred eighty-one thousand, nine hundred twenty".