20381988 has 24 divisors (see below), whose sum is σ = 51881760. Its totient is φ = 6176320.

The previous prime is 20381981. The next prime is 20381993. The reversal of 20381988 is 88918302.

It is not an unprimeable number, because it can be changed into a prime (20381981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77073 + ... + 77336.

It is an arithmetic number, because the mean of its divisors is an integer number (2161740).

Almost surely, 2^20381988 is an apocalyptic number.

It is an amenable number.

20381988 is an abundant number, since it is smaller than the sum of its proper divisors (31499772).

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

20381988 is a wasteful number, since it uses less digits than its factorization.

20381988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154427 (or 154425 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 20381988 is about 4514.6415140075. The cubic root of 20381988 is about 273.1589998117.

The spelling of 20381988 in words is "twenty million, three hundred eighty-one thousand, nine hundred eighty-eight".