20695517 has 2 divisors, whose sum is σ = 20695518. Its totient is φ = 20695516.

The previous prime is 20695483. The next prime is 20695537. The reversal of 20695517 is 71559602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20693401 + 2116 = 4549^2 + 46^2 .

It is a cyclic number.

It is not a de Polignac number, because 20695517 - 2⁶ = 20695453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20695537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10347758 + 10347759.

It is an arithmetic number, because the mean of its divisors is an integer number (10347759).

Almost surely, 2^20695517 is an apocalyptic number.

It is an amenable number.

20695517 is a deficient number, since it is larger than the sum of its proper divisors (1).

20695517 is an equidigital number, since it uses as much as digits as its factorization.

20695517 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18900, while the sum is 35.

The square root of 20695517 is about 4549.2325726434. The cubic root of 20695517 is about 274.5525152151.

It can be divided in two parts, 20695 and 517, that added together give a palindrome (21212).

The spelling of 20695517 in words is "twenty million, six hundred ninety-five thousand, five hundred seventeen".