87405201207721 has 2 divisors, whose sum is σ = 87405201207722. Its totient is φ = 87405201207720.

The previous prime is 87405201207647. The next prime is 87405201207743. The reversal of 87405201207721 is 12770210250478.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83875631156496 + 3529570051225 = 9158364^2 + 1878715^2 .

It is a cyclic number.

It is not a de Polignac number, because 87405201207721 - 2²⁵ = 87405167653289 is a prime.

It is not a weakly prime, because it can be changed into another prime (87405201207761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43702600603860 + 43702600603861.

It is an arithmetic number, because the mean of its divisors is an integer number (43702600603861).

Almost surely, 2^{87405201207721} is an apocalyptic number.

It is an amenable number.

87405201207721 is a deficient number, since it is larger than the sum of its proper divisors (1).

87405201207721 is an equidigital number, since it uses as much as digits as its factorization.

87405201207721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 439040, while the sum is 46.

The spelling of 87405201207721 in words is "eighty-seven trillion, four hundred five billion, two hundred one million, two hundred seven thousand, seven hundred twenty-one".