20151897389257 has 2 divisors, whose sum is σ = 20151897389258. Its totient is φ = 20151897389256.

The previous prime is 20151897389231. The next prime is 20151897389263. The reversal of 20151897389257 is 75298379815102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19978432636176 + 173464753081 = 4469724^2 + 416491^2 .

It is a cyclic number.

It is not a de Polignac number, because 20151897389257 - 2⁴³ = 11355804367049 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20151897389192 and 20151897389201.

It is not a weakly prime, because it can be changed into another prime (20151897389287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10075948694628 + 10075948694629.

It is an arithmetic number, because the mean of its divisors is an integer number (10075948694629).

Almost surely, 2^{20151897389257} is an apocalyptic number.

It is an amenable number.

20151897389257 is a deficient number, since it is larger than the sum of its proper divisors (1).

20151897389257 is an equidigital number, since it uses as much as digits as its factorization.

20151897389257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 76204800, while the sum is 67.

The spelling of 20151897389257 in words is "twenty trillion, one hundred fifty-one billion, eight hundred ninety-seven million, three hundred eighty-nine thousand, two hundred fifty-seven".