20021740 has 12 divisors (see below), whose sum is σ = 42045696. Its totient is φ = 8008688.

The previous prime is 20021737. The next prime is 20021741. The reversal of 20021740 is 4712002.

It is not an unprimeable number, because it can be changed into a prime (20021741) 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 3 ways as a sum of consecutive naturals, for example, 500524 + ... + 500563.

It is an arithmetic number, because the mean of its divisors is an integer number (3503808).

Almost surely, 2^20021740 is an apocalyptic number.

20021740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20021740 is an abundant number, since it is smaller than the sum of its proper divisors (22023956).

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

20021740 is a wasteful number, since it uses less digits than its factorization.

20021740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1001096 (or 1001094 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 20021740 is about 4474.5659007327. The cubic root of 20021740 is about 271.5400784430.

Adding to 20021740 its reverse (4712002), we get a palindrome (24733742).

It can be divided in two parts, 2002 and 1740, that multiplied together give a triangular number (3483480 = T₂₆₃₉).

The spelling of 20021740 in words is "twenty million, twenty-one thousand, seven hundred forty".