27721973 has 2 divisors, whose sum is σ = 27721974. Its totient is φ = 27721972.

The previous prime is 27721949. The next prime is 27721979. The reversal of 27721973 is 37912772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18130564 + 9591409 = 4258^2 + 3097^2 .

It is a cyclic number.

It is not a de Polignac number, because 27721973 - 2¹⁰ = 27720949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27721979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13860986 + 13860987.

It is an arithmetic number, because the mean of its divisors is an integer number (13860987).

Almost surely, 2^27721973 is an apocalyptic number.

It is an amenable number.

27721973 is a deficient number, since it is larger than the sum of its proper divisors (1).

27721973 is an equidigital number, since it uses as much as digits as its factorization.

27721973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37044, while the sum is 38.

The square root of 27721973 is about 5265.1659992825. The cubic root of 27721973 is about 302.6504881533.

The spelling of 27721973 in words is "twenty-seven million, seven hundred twenty-one thousand, nine hundred seventy-three".