18920271840 has 48 divisors (see below), whose sum is σ = 59598857808. Its totient is φ = 5045405696.

The previous prime is 18920271817. The next prime is 18920271871. The reversal of 18920271840 is 4817202981.

It is a tau number, because it is divible by the number of its divisors (48).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 18920271792 and 18920271801.

It is a congruent number.

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, 19708137 + ... + 19709096.

It is an arithmetic number, because the mean of its divisors is an integer number (1241642871).

Almost surely, 2^18920271840 is an apocalyptic number.

18920271840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18920271840 is an abundant number, since it is smaller than the sum of its proper divisors (40678585968).

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

18920271840 is a wasteful number, since it uses less digits than its factorization.

18920271840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39417251 (or 39417243 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 42.

The spelling of 18920271840 in words is "eighteen billion, nine hundred twenty million, two hundred seventy-one thousand, eight hundred forty".