2157197575669 has 2 divisors, whose sum is σ = 2157197575670. Its totient is φ = 2157197575668.

The previous prime is 2157197575667. The next prime is 2157197575691. The reversal of 2157197575669 is 9665757917512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1677703648644 + 479493927025 = 1295262^2 + 692455^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157197575669 - 2¹ = 2157197575667 is a prime.

It is a super-2 number, since 2×2157197575669² (a number of 25 digits) contains 22 as substring.

Together with 2157197575667, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2157197575598 and 2157197575607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2157197575667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078598787834 + 1078598787835.

It is an arithmetic number, because the mean of its divisors is an integer number (1078598787835).

Almost surely, 2^{2157197575669} is an apocalyptic number.

It is an amenable number.

2157197575669 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157197575669 is an equidigital number, since it uses as much as digits as its factorization.

2157197575669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 250047000, while the sum is 70.

The spelling of 2157197575669 in words is "two trillion, one hundred fifty-seven billion, one hundred ninety-seven million, five hundred seventy-five thousand, six hundred sixty-nine".