20748717 has 60 divisors (see below), whose sum is σ = 35726460. Its totient is φ = 11975040.

The previous prime is 20748713. The next prime is 20748719. The reversal of 20748717 is 71784702.

It can be written as a sum of positive squares in 2 ways, for example, as 11329956 + 9418761 = 3366^2 + 3069^2 .

It is not a de Polignac number, because 20748717 - 2² = 20748713 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20748713) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 284193 + ... + 284265.

It is an arithmetic number, because the mean of its divisors is an integer number (595441).

Almost surely, 2^20748717 is an apocalyptic number.

20748717 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20748717 is a deficient number, since it is larger than the sum of its proper divisors (14977743).

20748717 is a wasteful number, since it uses less digits than its factorization.

20748717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 116 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The square root of 20748717 is about 4555.0759598496. The cubic root of 20748717 is about 274.7875692781.

The spelling of 20748717 in words is "twenty million, seven hundred forty-eight thousand, seven hundred seventeen".