64077273721 has 2 divisors, whose sum is σ = 64077273722. Its totient is φ = 64077273720.

The previous prime is 64077273619. The next prime is 64077273739. The reversal of 64077273721 is 12737277046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50589006400 + 13488267321 = 224920^2 + 116139^2 .

It is a cyclic number.

It is not a de Polignac number, because 64077273721 - 2⁹ = 64077273209 is a prime.

It is not a weakly prime, because it can be changed into another prime (64077273781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32038636860 + 32038636861.

It is an arithmetic number, because the mean of its divisors is an integer number (32038636861).

Almost surely, 2^64077273721 is an apocalyptic number.

It is an amenable number.

64077273721 is a deficient number, since it is larger than the sum of its proper divisors (1).

64077273721 is an equidigital number, since it uses as much as digits as its factorization.

64077273721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 691488, while the sum is 46.

The spelling of 64077273721 in words is "sixty-four billion, seventy-seven million, two hundred seventy-three thousand, seven hundred twenty-one".