497138997821 has 2 divisors, whose sum is σ = 497138997822. Its totient is φ = 497138997820.

The previous prime is 497138997811. The next prime is 497138997917. The reversal of 497138997821 is 128799831794.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 497111013721 + 27984100 = 705061^2 + 5290^2 .

It is a cyclic number.

It is not a de Polignac number, because 497138997821 - 2¹⁸ = 497138735677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (497138997811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 248569498910 + 248569498911.

It is an arithmetic number, because the mean of its divisors is an integer number (248569498911).

Almost surely, 2^497138997821 is an apocalyptic number.

It is an amenable number.

497138997821 is a deficient number, since it is larger than the sum of its proper divisors (1).

497138997821 is an equidigital number, since it uses as much as digits as its factorization.

497138997821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54867456, while the sum is 68.

The spelling of 497138997821 in words is "four hundred ninety-seven billion, one hundred thirty-eight million, nine hundred ninety-seven thousand, eight hundred twenty-one".