20138136457 has 2 divisors, whose sum is σ = 20138136458. Its totient is φ = 20138136456.

The previous prime is 20138136439. The next prime is 20138136493. The reversal of 20138136457 is 75463183102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19604480256 + 533656201 = 140016^2 + 23101^2 .

It is a cyclic number.

It is not a de Polignac number, because 20138136457 - 2⁷ = 20138136329 is a prime.

It is not a weakly prime, because it can be changed into another prime (20138136407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10069068228 + 10069068229.

It is an arithmetic number, because the mean of its divisors is an integer number (10069068229).

Almost surely, 2^20138136457 is an apocalyptic number.

It is an amenable number.

20138136457 is a deficient number, since it is larger than the sum of its proper divisors (1).

20138136457 is an equidigital number, since it uses as much as digits as its factorization.

20138136457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 20138136457 in words is "twenty billion, one hundred thirty-eight million, one hundred thirty-six thousand, four hundred fifty-seven".