2123518697257 has 4 divisors (see below), whose sum is σ = 2123523684100. Its totient is φ = 2123513710416.

The previous prime is 2123518697233. The next prime is 2123518697281. The reversal of 2123518697257 is 7527968153212.

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

It is an interprime number because it is at equal distance from previous prime (2123518697233) and next prime (2123518697281).

It can be written as a sum of positive squares in 2 ways, for example, as 1076424925081 + 1047093772176 = 1037509^2 + 1023276^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2123518697257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2123518697957) 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, 1788198 + ... + 2728495.

It is an arithmetic number, because the mean of its divisors is an integer number (530880921025).

Almost surely, 2^{2123518697257} is an apocalyptic number.

It is an amenable number.

2123518697257 is a deficient number, since it is larger than the sum of its proper divisors (4986843).

2123518697257 is an equidigital number, since it uses as much as digits as its factorization.

2123518697257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4986842.

The product of its digits is 12700800, while the sum is 58.

The spelling of 2123518697257 in words is "two trillion, one hundred twenty-three billion, five hundred eighteen million, six hundred ninety-seven thousand, two hundred fifty-seven".