1377608198821 has 2 divisors, whose sum is σ = 1377608198822. Its totient is φ = 1377608198820.

The previous prime is 1377608198773. The next prime is 1377608198873. The reversal of 1377608198821 is 1288918067731.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1210561065025 + 167047133796 = 1100255^2 + 408714^2 .

It is a cyclic number.

It is not a de Polignac number, because 1377608198821 - 2²⁵ = 1377574644389 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1377608198821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1377608168821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 688804099410 + 688804099411.

It is an arithmetic number, because the mean of its divisors is an integer number (688804099411).

Almost surely, 2^{1377608198821} is an apocalyptic number.

It is an amenable number.

1377608198821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1377608198821 is an equidigital number, since it uses as much as digits as its factorization.

1377608198821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8128512, while the sum is 61.

The spelling of 1377608198821 in words is "one trillion, three hundred seventy-seven billion, six hundred eight million, one hundred ninety-eight thousand, eight hundred twenty-one".