65570720521 has 2 divisors, whose sum is σ = 65570720522. Its totient is φ = 65570720520.

The previous prime is 65570720491. The next prime is 65570720533. The reversal of 65570720521 is 12502707556.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52285852921 + 13284867600 = 228661^2 + 115260^2 .

It is a cyclic number.

It is not a de Polignac number, because 65570720521 - 2⁵ = 65570720489 is a prime.

It is a super-2 number, since 2×65570720521² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (65570720561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32785360260 + 32785360261.

It is an arithmetic number, because the mean of its divisors is an integer number (32785360261).

Almost surely, 2^65570720521 is an apocalyptic number.

It is an amenable number.

65570720521 is a deficient number, since it is larger than the sum of its proper divisors (1).

65570720521 is an equidigital number, since it uses as much as digits as its factorization.

65570720521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 147000, while the sum is 40.

The spelling of 65570720521 in words is "sixty-five billion, five hundred seventy million, seven hundred twenty thousand, five hundred twenty-one".