20490642 has 12 divisors (see below), whose sum is σ = 44396430. Its totient is φ = 6830208.

The previous prime is 20490623. The next prime is 20490649. The reversal of 20490642 is 24609402.

It can be written as a sum of positive squares in only one way, i.e., 15992001 + 4498641 = 3999^2 + 2121^2 .

It is not an unprimeable number, because it can be changed into a prime (20490649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 569167 + ... + 569202.

Almost surely, 2^20490642 is an apocalyptic number.

20490642 is an abundant number, since it is smaller than the sum of its proper divisors (23905788).

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

20490642 is a wasteful number, since it uses less digits than its factorization.

20490642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138377 (or 1138374 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 20490642 is about 4526.6590328851. The cubic root of 20490642 is about 273.6435327520.

The spelling of 20490642 in words is "twenty million, four hundred ninety thousand, six hundred forty-two".