18821945540 has 48 divisors (see below), whose sum is σ = 39683685888. Its totient is φ = 7498817664.

The previous prime is 18821945521. The next prime is 18821945561. The reversal of 18821945540 is 4554912881.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9122549 + ... + 9124611.

It is an arithmetic number, because the mean of its divisors is an integer number (826743456).

Almost surely, 2^18821945540 is an apocalyptic number.

18821945540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18821945540 is an abundant number, since it is smaller than the sum of its proper divisors (20861740348).

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

18821945540 is a wasteful number, since it uses less digits than its factorization.

18821945540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3668 (or 3666 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 47.

The spelling of 18821945540 in words is "eighteen billion, eight hundred twenty-one million, nine hundred forty-five thousand, five hundred forty".