549663721 has 2 divisors, whose sum is σ = 549663722. Its totient is φ = 549663720.

The previous prime is 549663701. The next prime is 549663739. The reversal of 549663721 is 127366945.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 481188096 + 68475625 = 21936^2 + 8275^2 .

It is a cyclic number.

It is not a de Polignac number, because 549663721 - 2²³ = 541275113 is a prime.

It is not a weakly prime, because it can be changed into another prime (549663701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 274831860 + 274831861.

It is an arithmetic number, because the mean of its divisors is an integer number (274831861).

Almost surely, 2^549663721 is an apocalyptic number.

It is an amenable number.

549663721 is a deficient number, since it is larger than the sum of its proper divisors (1).

549663721 is an equidigital number, since it uses as much as digits as its factorization.

549663721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272160, while the sum is 43.

The square root of 549663721 is about 23444.9082105262. The cubic root of 549663721 is about 819.1542544132.

The spelling of 549663721 in words is "five hundred forty-nine million, six hundred sixty-three thousand, seven hundred twenty-one".