20561707 has 2 divisors, whose sum is σ = 20561708. Its totient is φ = 20561706.

The previous prime is 20561693. The next prime is 20561719. The reversal of 20561707 is 70716502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20561707 - 2⁷ = 20561579 is a prime.

It is not a weakly prime, because it can be changed into another prime (20561767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10280853 + 10280854.

It is an arithmetic number, because the mean of its divisors is an integer number (10280854).

Almost surely, 2^20561707 is an apocalyptic number.

20561707 is a deficient number, since it is larger than the sum of its proper divisors (1).

20561707 is an equidigital number, since it uses as much as digits as its factorization.

20561707 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 20561707 is about 4534.5018469508. The cubic root of 20561707 is about 273.9595150371.

The spelling of 20561707 in words is "twenty million, five hundred sixty-one thousand, seven hundred seven".