1518621640 has 16 divisors (see below), whose sum is σ = 3416898780. Its totient is φ = 607448640.

The previous prime is 1518621623. The next prime is 1518621641. The reversal of 1518621640 is 461268151.

It can be written as a sum of positive squares in 2 ways, for example, as 1518349156 + 272484 = 38966^2 + 522^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1518621596 and 1518621605.

It is not an unprimeable number, because it can be changed into a prime (1518621641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18982731 + ... + 18982810.

Almost surely, 2^1518621640 is an apocalyptic number.

1518621640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1518621640 is an abundant number, since it is smaller than the sum of its proper divisors (1898277140).

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

1518621640 is a wasteful number, since it uses less digits than its factorization.

1518621640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37965552 (or 37965548 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 1518621640 is about 38969.4962759336. The cubic root of 1518621640 is about 1149.4317646397.

Adding to 1518621640 its reverse (461268151), we get a palindrome (1979889791).

The spelling of 1518621640 in words is "one billion, five hundred eighteen million, six hundred twenty-one thousand, six hundred forty".