20722740 has 24 divisors (see below), whose sum is σ = 58023840. Its totient is φ = 5526048.

The previous prime is 20722687. The next prime is 20722769. The reversal of 20722740 is 4722702.

It is a self number, because there is not a number n which added to its sum of digits gives 20722740.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 172630 + ... + 172749.

It is an arithmetic number, because the mean of its divisors is an integer number (2417660).

Almost surely, 2^20722740 is an apocalyptic number.

20722740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20722740 is an abundant number, since it is smaller than the sum of its proper divisors (37301100).

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

20722740 is a wasteful number, since it uses less digits than its factorization.

20722740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345391 (or 345389 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 24.

The square root of 20722740 is about 4552.2236324680. The cubic root of 20722740 is about 274.6728451130.

The spelling of 20722740 in words is "twenty million, seven hundred twenty-two thousand, seven hundred forty".