20716761 has 16 divisors (see below), whose sum is σ = 31497984. Its totient is φ = 11998464.

The previous prime is 20716757. The next prime is 20716769. The reversal of 20716761 is 16761702.

It is a happy number.

It is not a de Polignac number, because 20716761 - 2² = 20716757 is a prime.

It is a super-2 number, since 2×20716761² = 858368372662242, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20716769) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 14961 + ... + 16286.

It is an arithmetic number, because the mean of its divisors is an integer number (1968624).

Almost surely, 2^20716761 is an apocalyptic number.

It is an amenable number.

20716761 is a deficient number, since it is larger than the sum of its proper divisors (10781223).

20716761 is a wasteful number, since it uses less digits than its factorization.

20716761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31280.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 20716761 is about 4551.5668730669. The cubic root of 20716761 is about 274.6464260372.

The spelling of 20716761 in words is "twenty million, seven hundred sixteen thousand, seven hundred sixty-one".