21038952017 has 2 divisors, whose sum is σ = 21038952018. Its totient is φ = 21038952016.

The previous prime is 21038951993. The next prime is 21038952097. The reversal of 21038952017 is 71025983012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20323068481 + 715883536 = 142559^2 + 26756^2 .

It is a cyclic number.

It is not a de Polignac number, because 21038952017 - 2²⁶ = 20971843153 is a prime.

It is not a weakly prime, because it can be changed into another prime (21038952097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10519476008 + 10519476009.

It is an arithmetic number, because the mean of its divisors is an integer number (10519476009).

Almost surely, 2^21038952017 is an apocalyptic number.

It is an amenable number.

21038952017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21038952017 is an equidigital number, since it uses as much as digits as its factorization.

21038952017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 38.

The spelling of 21038952017 in words is "twenty-one billion, thirty-eight million, nine hundred fifty-two thousand, seventeen".