66400562537 has 2 divisors, whose sum is σ = 66400562538. Its totient is φ = 66400562536.

The previous prime is 66400562533. The next prime is 66400562587. The reversal of 66400562537 is 73526500466.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54616157401 + 11784405136 = 233701^2 + 108556^2 .

It is a cyclic number.

It is not a de Polignac number, because 66400562537 - 2² = 66400562533 is a prime.

It is not a weakly prime, because it can be changed into another prime (66400562533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33200281268 + 33200281269.

It is an arithmetic number, because the mean of its divisors is an integer number (33200281269).

Almost surely, 2^66400562537 is an apocalyptic number.

It is an amenable number.

66400562537 is a deficient number, since it is larger than the sum of its proper divisors (1).

66400562537 is an equidigital number, since it uses as much as digits as its factorization.

66400562537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 907200, while the sum is 44.

The spelling of 66400562537 in words is "sixty-six billion, four hundred million, five hundred sixty-two thousand, five hundred thirty-seven".