18919919120 has 40 divisors (see below), whose sum is σ = 43995498840. Its totient is φ = 7566817280.

The previous prime is 18919919099. The next prime is 18919919141. The reversal of 18919919120 is 2191991981.

It is an interprime number because it is at equal distance from previous prime (18919919099) and next prime (18919919141).

It can be written as a sum of positive squares in 4 ways, for example, as 3372821776 + 15547097344 = 58076^2 + 124688^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 679880 + ... + 707160.

It is an arithmetic number, because the mean of its divisors is an integer number (1099887471).

Almost surely, 2^18919919120 is an apocalyptic number.

18919919120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18919919120 is an abundant number, since it is smaller than the sum of its proper divisors (25075579720).

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

18919919120 is a wasteful number, since it uses less digits than its factorization.

18919919120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35963 (or 35957 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 50.

The spelling of 18919919120 in words is "eighteen billion, nine hundred nineteen million, nine hundred nineteen thousand, one hundred twenty".