20109523381 has 2 divisors, whose sum is σ = 20109523382. Its totient is φ = 20109523380.

The previous prime is 20109523351. The next prime is 20109523409. The reversal of 20109523381 is 18332590102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19967103025 + 142420356 = 141305^2 + 11934^2 .

It is a cyclic number.

It is not a de Polignac number, because 20109523381 - 2⁵ = 20109523349 is a prime.

It is a super-2 number, since 2×20109523381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20109523321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10054761690 + 10054761691.

It is an arithmetic number, because the mean of its divisors is an integer number (10054761691).

Almost surely, 2^20109523381 is an apocalyptic number.

It is an amenable number.

20109523381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20109523381 is an equidigital number, since it uses as much as digits as its factorization.

20109523381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 34.

The spelling of 20109523381 in words is "twenty billion, one hundred nine million, five hundred twenty-three thousand, three hundred eighty-one".