18911903457878 has 8 divisors (see below), whose sum is σ = 28367880097872. Its totient is φ = 9455943425256.

The previous prime is 18911903457859. The next prime is 18911903457949. The reversal of 18911903457878 is 87875430911981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 746225 + ... + 6195212.

It is an arithmetic number, because the mean of its divisors is an integer number (3545985012234).

Almost surely, 2^{18911903457878} is an apocalyptic number.

18911903457878 is a deficient number, since it is larger than the sum of its proper divisors (9455976639994).

18911903457878 is a wasteful number, since it uses less digits than its factorization.

18911903457878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8303686.

The product of its (nonzero) digits is 121927680, while the sum is 71.

The spelling of 18911903457878 in words is "eighteen trillion, nine hundred eleven billion, nine hundred three million, four hundred fifty-seven thousand, eight hundred seventy-eight".