20751705 has 48 divisors (see below), whose sum is σ = 40797120. Its totient is φ = 9673344.

The previous prime is 20751691. The next prime is 20751761. The reversal of 20751705 is 50715702.

It is not a de Polignac number, because 20751705 - 2⁹ = 20751193 is a prime.

It is a Curzon number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 10182 + ... + 12048.

It is an arithmetic number, because the mean of its divisors is an integer number (849940).

Almost surely, 2^20751705 is an apocalyptic number.

It is an amenable number.

20751705 is a deficient number, since it is larger than the sum of its proper divisors (20045415).

20751705 is a wasteful number, since it uses less digits than its factorization.

20751705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1910 (or 1907 counting only the distinct ones).

The product of its (nonzero) digits is 2450, while the sum is 27.

The square root of 20751705 is about 4555.4039337912. The cubic root of 20751705 is about 274.8007592639.

The spelling of 20751705 in words is "twenty million, seven hundred fifty-one thousand, seven hundred five".