2157667 has 2 divisors, whose sum is σ = 2157668. Its totient is φ = 2157666.

The previous prime is 2157641. The next prime is 2157671. The reversal of 2157667 is 7667512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2157667 - 2⁷ = 2157539 is a prime.

2157667 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2157677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078833 + 1078834.

It is an arithmetic number, because the mean of its divisors is an integer number (1078834).

2^2157667 is an apocalyptic number.

2157667 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157667 is an equidigital number, since it uses as much as digits as its factorization.

2157667 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17640, while the sum is 34.

The square root of 2157667 is about 1468.8999285179. The cubic root of 2157667 is about 129.2195248571.

The spelling of 2157667 in words is "two million, one hundred fifty-seven thousand, six hundred sixty-seven".