166821827 has 2 divisors, whose sum is σ = 166821828. Its totient is φ = 166821826.

The previous prime is 166821817. The next prime is 166821841. The reversal of 166821827 is 728128661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 166821827 - 2¹² = 166817731 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166821817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83410913 + 83410914.

It is an arithmetic number, because the mean of its divisors is an integer number (83410914).

Almost surely, 2^166821827 is an apocalyptic number.

166821827 is a deficient number, since it is larger than the sum of its proper divisors (1).

166821827 is an equidigital number, since it uses as much as digits as its factorization.

166821827 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64512, while the sum is 41.

The square root of 166821827 is about 12915.9524232633. The cubic root of 166821827 is about 550.4919312254.

The spelling of 166821827 in words is "one hundred sixty-six million, eight hundred twenty-one thousand, eight hundred twenty-seven".