20281994 has 8 divisors (see below), whose sum is σ = 31245348. Its totient is φ = 9866880.

The previous prime is 20281993. The next prime is 20281997. The reversal of 20281994 is 49918202.

It can be written as a sum of positive squares in 2 ways, for example, as 19404025 + 877969 = 4405^2 + 937^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×20281994² = 822718561232072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20281993) 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 3 ways as a sum of consecutive naturals, for example, 136967 + ... + 137114.

Almost surely, 2^20281994 is an apocalyptic number.

20281994 is a deficient number, since it is larger than the sum of its proper divisors (10963354).

20281994 is a wasteful number, since it uses less digits than its factorization.

20281994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274120.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 20281994 is about 4503.5534858598. The cubic root of 20281994 is about 272.7115614316.

The spelling of 20281994 in words is "twenty million, two hundred eighty-one thousand, nine hundred ninety-four".