20487890 has 32 divisors (see below), whose sum is σ = 41109120. Its totient is φ = 7305984.

The previous prime is 20487877. The next prime is 20487893. The reversal of 20487890 is 9878402.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is not an unprimeable number, because it can be changed into a prime (20487893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59 + ... + 6401.

It is an arithmetic number, because the mean of its divisors is an integer number (1284660).

Almost surely, 2^20487890 is an apocalyptic number.

20487890 is an abundant number, since it is smaller than the sum of its proper divisors (20621230).

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

20487890 is a wasteful number, since it uses less digits than its factorization.

20487890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6386.

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 20487890 is about 4526.3550457294. The cubic root of 20487890 is about 273.6312816193.

The spelling of 20487890 in words is "twenty million, four hundred eighty-seven thousand, eight hundred ninety".