655249551721 has 2 divisors, whose sum is σ = 655249551722. Its totient is φ = 655249551720.

The previous prime is 655249551701. The next prime is 655249551769. The reversal of 655249551721 is 127155942556.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 334938830121 + 320310721600 = 578739^2 + 565960^2 .

It is a cyclic number.

It is not a de Polignac number, because 655249551721 - 2¹¹ = 655249549673 is a prime.

It is not a weakly prime, because it can be changed into another prime (655249551701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327624775860 + 327624775861.

It is an arithmetic number, because the mean of its divisors is an integer number (327624775861).

Almost surely, 2^655249551721 is an apocalyptic number.

It is an amenable number.

655249551721 is a deficient number, since it is larger than the sum of its proper divisors (1).

655249551721 is an equidigital number, since it uses as much as digits as its factorization.

655249551721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780000, while the sum is 52.

The spelling of 655249551721 in words is "six hundred fifty-five billion, two hundred forty-nine million, five hundred fifty-one thousand, seven hundred twenty-one".