2157679 has 2 divisors, whose sum is σ = 2157680. Its totient is φ = 2157678.

The previous prime is 2157677. The next prime is 2157709. The reversal of 2157679 is 9767512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2157679 - 2¹ = 2157677 is a prime.

Together with 2157677, it forms a pair of twin primes.

It is a Chen prime.

It is a d-powerful number, because it can be written as 2²¹ + 1 + 5³ + 7 + 6⁴ + 7² + 9⁵ .

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2157671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078839 + 1078840.

It is an arithmetic number, because the mean of its divisors is an integer number (1078840).

2^2157679 is an apocalyptic number.

2157679 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157679 is an equidigital number, since it uses as much as digits as its factorization.

2157679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26460, while the sum is 37.

The square root of 2157679 is about 1468.9040132017. The cubic root of 2157679 is about 129.2197644108.

The spelling of 2157679 in words is "two million, one hundred fifty-seven thousand, six hundred seventy-nine".