168746561537 has 2 divisors, whose sum is σ = 168746561538. Its totient is φ = 168746561536.

The previous prime is 168746561497. The next prime is 168746561573. The reversal of 168746561537 is 735165647861.

Together with next prime (168746561573) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153790249921 + 14956311616 = 392161^2 + 122296^2 .

It is a cyclic number.

It is not a de Polignac number, because 168746561537 - 2⁸ = 168746561281 is a prime.

It is not a weakly prime, because it can be changed into another prime (168746561587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84373280768 + 84373280769.

It is an arithmetic number, because the mean of its divisors is an integer number (84373280769).

Almost surely, 2^168746561537 is an apocalyptic number.

It is an amenable number.

168746561537 is a deficient number, since it is larger than the sum of its proper divisors (1).

168746561537 is an equidigital number, since it uses as much as digits as its factorization.

168746561537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25401600, while the sum is 59.

The spelling of 168746561537 in words is "one hundred sixty-eight billion, seven hundred forty-six million, five hundred sixty-one thousand, five hundred thirty-seven".