27821993 has 2 divisors, whose sum is σ = 27821994. Its totient is φ = 27821992.

The previous prime is 27821987. The next prime is 27822001. The reversal of 27821993 is 39912872.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19998784 + 7823209 = 4472^2 + 2797^2 .

It is a cyclic number.

It is not a de Polignac number, because 27821993 - 2⁴ = 27821977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 27821993.

It is not a weakly prime, because it can be changed into another prime (27821093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13910996 + 13910997.

It is an arithmetic number, because the mean of its divisors is an integer number (13910997).

Almost surely, 2^27821993 is an apocalyptic number.

It is an amenable number.

27821993 is a deficient number, since it is larger than the sum of its proper divisors (1).

27821993 is an equidigital number, since it uses as much as digits as its factorization.

27821993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 41.

The square root of 27821993 is about 5274.6557233624. The cubic root of 27821993 is about 303.0140357370.

The spelling of 27821993 in words is "twenty-seven million, eight hundred twenty-one thousand, nine hundred ninety-three".