2157197575679 has 4 divisors (see below), whose sum is σ = 2170937687784. Its totient is φ = 2143457463576.

The previous prime is 2157197575669. The next prime is 2157197575691. The reversal of 2157197575679 is 9765757917512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2157197575679 - 2³² = 2152902608383 is a prime.

It is a super-2 number, since 2×2157197575679² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157197575609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6870055817 + ... + 6870056130.

It is an arithmetic number, because the mean of its divisors is an integer number (542734421946).

Almost surely, 2^{2157197575679} is an apocalyptic number.

2157197575679 is a deficient number, since it is larger than the sum of its proper divisors (13740112105).

2157197575679 is a wasteful number, since it uses less digits than its factorization.

2157197575679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13740112104.

The product of its digits is 291721500, while the sum is 71.

The spelling of 2157197575679 in words is "two trillion, one hundred fifty-seven billion, one hundred ninety-seven million, five hundred seventy-five thousand, six hundred seventy-nine".