20986117 has 2 divisors, whose sum is σ = 20986118. Its totient is φ = 20986116.

The previous prime is 20986093. The next prime is 20986151. The reversal of 20986117 is 71168902.

It is a happy number.

It is an a-pointer prime, because the next prime (20986151) can be obtained adding 20986117 to its sum of digits (34).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13771521 + 7214596 = 3711^2 + 2686^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20986117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20986157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10493058 + 10493059.

It is an arithmetic number, because the mean of its divisors is an integer number (10493059).

Almost surely, 2^20986117 is an apocalyptic number.

It is an amenable number.

20986117 is a deficient number, since it is larger than the sum of its proper divisors (1).

20986117 is an equidigital number, since it uses as much as digits as its factorization.

20986117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 20986117 is about 4581.0606850379. The cubic root of 20986117 is about 275.8316071811.

It can be divided in two parts, 20 and 986117, that multiplied together give a triangular number (19722340 = T₆₂₈₀).

The spelling of 20986117 in words is "twenty million, nine hundred eighty-six thousand, one hundred seventeen".