2157971008357 has 2 divisors, whose sum is σ = 2157971008358. Its totient is φ = 2157971008356.

The previous prime is 2157971008313. The next prime is 2157971008363. The reversal of 2157971008357 is 7538001797512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1913327999361 + 244643008996 = 1383231^2 + 494614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2157971008357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2157971008298 and 2157971008307.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2157971008387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078985504178 + 1078985504179.

It is an arithmetic number, because the mean of its divisors is an integer number (1078985504179).

Almost surely, 2^{2157971008357} is an apocalyptic number.

It is an amenable number.

2157971008357 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157971008357 is an equidigital number, since it uses as much as digits as its factorization.

2157971008357 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3704400, while the sum is 55.

The spelling of 2157971008357 in words is "two trillion, one hundred fifty-seven billion, nine hundred seventy-one million, eight thousand, three hundred fifty-seven".