654815657681 has 2 divisors, whose sum is σ = 654815657682. Its totient is φ = 654815657680.

The previous prime is 654815657597. The next prime is 654815657707. The reversal of 654815657681 is 186756518456.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 570666930625 + 84148727056 = 755425^2 + 290084^2 .

It is a cyclic number.

It is not a de Polignac number, because 654815657681 - 2¹⁴ = 654815641297 is a prime.

It is a super-2 number, since 2×654815657681² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (654815657381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327407828840 + 327407828841.

It is an arithmetic number, because the mean of its divisors is an integer number (327407828841).

Almost surely, 2^654815657681 is an apocalyptic number.

It is an amenable number.

654815657681 is a deficient number, since it is larger than the sum of its proper divisors (1).

654815657681 is an equidigital number, since it uses as much as digits as its factorization.

654815657681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384000, while the sum is 62.

The spelling of 654815657681 in words is "six hundred fifty-four billion, eight hundred fifteen million, six hundred fifty-seven thousand, six hundred eighty-one".