65720533978537 has 2 divisors, whose sum is σ = 65720533978538. Its totient is φ = 65720533978536.

The previous prime is 65720533978493. The next prime is 65720533978543. The reversal of 65720533978537 is 73587933502756.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60963864580096 + 4756669398441 = 7807936^2 + 2180979^2 .

It is a cyclic number.

It is not a de Polignac number, because 65720533978537 - 2¹⁵ = 65720533945769 is a prime.

It is not a weakly prime, because it can be changed into another prime (65720533978037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32860266989268 + 32860266989269.

It is an arithmetic number, because the mean of its divisors is an integer number (32860266989269).

Almost surely, 2^{65720533978537} is an apocalyptic number.

It is an amenable number.

65720533978537 is a deficient number, since it is larger than the sum of its proper divisors (1).

65720533978537 is an equidigital number, since it uses as much as digits as its factorization.

65720533978537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1000188000, while the sum is 70.

The spelling of 65720533978537 in words is "sixty-five trillion, seven hundred twenty billion, five hundred thirty-three million, nine hundred seventy-eight thousand, five hundred thirty-seven".