68722631557 has 2 divisors, whose sum is σ = 68722631558. Its totient is φ = 68722631556.

The previous prime is 68722631501. The next prime is 68722631587. The reversal of 68722631557 is 75513622786.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61312692996 + 7409938561 = 247614^2 + 86081^2 .

It is a cyclic number.

It is not a de Polignac number, because 68722631557 - 2¹⁹ = 68722107269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68722631587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34361315778 + 34361315779.

It is an arithmetic number, because the mean of its divisors is an integer number (34361315779).

Almost surely, 2^68722631557 is an apocalyptic number.

It is an amenable number.

68722631557 is a deficient number, since it is larger than the sum of its proper divisors (1).

68722631557 is an equidigital number, since it uses as much as digits as its factorization.

68722631557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4233600, while the sum is 52.

The spelling of 68722631557 in words is "sixty-eight billion, seven hundred twenty-two million, six hundred thirty-one thousand, five hundred fifty-seven".