18687891980 has 12 divisors (see below), whose sum is σ = 39244573200. Its totient is φ = 7475156784.

The previous prime is 18687891979. The next prime is 18687891983. The reversal of 18687891980 is 8919878681.

It is a super-2 number, since 2×18687891980² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18687891983) 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, 467197280 + ... + 467197319.

It is an arithmetic number, because the mean of its divisors is an integer number (3270381100).

Almost surely, 2^18687891980 is an apocalyptic number.

18687891980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18687891980 is an abundant number, since it is smaller than the sum of its proper divisors (20556681220).

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

18687891980 is a wasteful number, since it uses less digits than its factorization.

18687891980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934394608 (or 934394606 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 65.

The spelling of 18687891980 in words is "eighteen billion, six hundred eighty-seven million, eight hundred ninety-one thousand, nine hundred eighty".