20281340 has 24 divisors (see below), whose sum is σ = 45096912. Its totient is φ = 7635200.

The previous prime is 20281333. The next prime is 20281367. The reversal of 20281340 is 4318202.

20281340 = T₄₀₁ + T₄₀₂ + ... + T₅₇₀.

It is a super-2 number, since 2×20281340² = 822665504391200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29486 + ... + 30165.

It is an arithmetic number, because the mean of its divisors is an integer number (1879038).

Almost surely, 2^20281340 is an apocalyptic number.

20281340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20281340 is an abundant number, since it is smaller than the sum of its proper divisors (24815572).

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

20281340 is a wasteful number, since it uses less digits than its factorization.

20281340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59677 (or 59675 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 20281340 is about 4503.4808759447. The cubic root of 20281340 is about 272.7086301735.

Adding to 20281340 its reverse (4318202), we get a palindrome (24599542).

The spelling of 20281340 in words is "twenty million, two hundred eighty-one thousand, three hundred forty".