1621148553769 has 2 divisors, whose sum is σ = 1621148553770. Its totient is φ = 1621148553768.

The previous prime is 1621148553719. The next prime is 1621148553799. The reversal of 1621148553769 is 9673558411261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1609155675625 + 11992878144 = 1268525^2 + 109512^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621148553769 - 2¹⁵ = 1621148521001 is a prime.

It is a super-2 number, since 2×1621148553769² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1621148553719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810574276884 + 810574276885.

It is an arithmetic number, because the mean of its divisors is an integer number (810574276885).

Almost surely, 2^{1621148553769} is an apocalyptic number.

It is an amenable number.

1621148553769 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621148553769 is an equidigital number, since it uses as much as digits as its factorization.

1621148553769 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10886400, while the sum is 58.

The spelling of 1621148553769 in words is "one trillion, six hundred twenty-one billion, one hundred forty-eight million, five hundred fifty-three thousand, seven hundred sixty-nine".