20942917 has 2 divisors, whose sum is σ = 20942918. Its totient is φ = 20942916.

The previous prime is 20942899. The next prime is 20942951. The reversal of 20942917 is 71924902.

It is a happy number.

It is an a-pointer prime, because the next prime (20942951) can be obtained adding 20942917 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., 14394436 + 6548481 = 3794^2 + 2559^2 .

It is a cyclic number.

It is not a de Polignac number, because 20942917 - 2²³ = 12554309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20942417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10471458 + 10471459.

It is an arithmetic number, because the mean of its divisors is an integer number (10471459).

Almost surely, 2^20942917 is an apocalyptic number.

It is an amenable number.

20942917 is a deficient number, since it is larger than the sum of its proper divisors (1).

20942917 is an equidigital number, since it uses as much as digits as its factorization.

20942917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 20942917 is about 4576.3431908020. The cubic root of 20942917 is about 275.6422103667.

The spelling of 20942917 in words is "twenty million, nine hundred forty-two thousand, nine hundred seventeen".