18851620044 has 12 divisors (see below), whose sum is σ = 43987113464. Its totient is φ = 6283873344.

The previous prime is 18851620037. The next prime is 18851620049. The reversal of 18851620044 is 44002615881.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 18851619984 and 18851620011.

It is not an unprimeable number, because it can be changed into a prime (18851620049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 785484157 + ... + 785484180.

Almost surely, 2^18851620044 is an apocalyptic number.

It is an amenable number.

18851620044 is an abundant number, since it is smaller than the sum of its proper divisors (25135493420).

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

18851620044 is a wasteful number, since it uses less digits than its factorization.

18851620044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1570968344 (or 1570968342 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 39.

The spelling of 18851620044 in words is "eighteen billion, eight hundred fifty-one million, six hundred twenty thousand, forty-four".