20756713 has 4 divisors (see below), whose sum is σ = 20876868. Its totient is φ = 20636560.

The previous prime is 20756707. The next prime is 20756717. The reversal of 20756713 is 31765702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8450649 + 12306064 = 2907^2 + 3508^2 .

It is a cyclic number.

It is not a de Polignac number, because 20756713 - 2²¹ = 18659561 is a prime.

It is a super-2 number, since 2×20756713² = 861682269128738, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20756717) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59818 + ... + 60163.

It is an arithmetic number, because the mean of its divisors is an integer number (5219217).

Almost surely, 2^20756713 is an apocalyptic number.

It is an amenable number.

20756713 is a deficient number, since it is larger than the sum of its proper divisors (120155).

20756713 is a wasteful number, since it uses less digits than its factorization.

20756713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120154.

The product of its (nonzero) digits is 8820, while the sum is 31.

The square root of 20756713 is about 4555.9535774632. The cubic root of 20756713 is about 274.8228633353.

The spelling of 20756713 in words is "twenty million, seven hundred fifty-six thousand, seven hundred thirteen".