20138900897 has 2 divisors, whose sum is σ = 20138900898. Its totient is φ = 20138900896.

The previous prime is 20138900819. The next prime is 20138900933. The reversal of 20138900897 is 79800983102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18894151936 + 1244748961 = 137456^2 + 35281^2 .

It is a cyclic number.

It is not a de Polignac number, because 20138900897 - 2¹² = 20138896801 is a prime.

It is not a weakly prime, because it can be changed into another prime (20138900597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10069450448 + 10069450449.

It is an arithmetic number, because the mean of its divisors is an integer number (10069450449).

Almost surely, 2^20138900897 is an apocalyptic number.

It is an amenable number.

20138900897 is a deficient number, since it is larger than the sum of its proper divisors (1).

20138900897 is an equidigital number, since it uses as much as digits as its factorization.

20138900897 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 47.

The spelling of 20138900897 in words is "twenty billion, one hundred thirty-eight million, nine hundred thousand, eight hundred ninety-seven".