20170235909 has 2 divisors, whose sum is σ = 20170235910. Its totient is φ = 20170235908.

The previous prime is 20170235867. The next prime is 20170235941. The reversal of 20170235909 is 90953207102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20023099009 + 147136900 = 141503^2 + 12130^2 .

It is a cyclic number.

It is not a de Polignac number, because 20170235909 - 2³² = 15875268613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20170235009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10085117954 + 10085117955.

It is an arithmetic number, because the mean of its divisors is an integer number (10085117955).

Almost surely, 2^20170235909 is an apocalyptic number.

It is an amenable number.

20170235909 is a deficient number, since it is larger than the sum of its proper divisors (1).

20170235909 is an equidigital number, since it uses as much as digits as its factorization.

20170235909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34020, while the sum is 38.

The spelling of 20170235909 in words is "twenty billion, one hundred seventy million, two hundred thirty-five thousand, nine hundred nine".