1661057837399 has 2 divisors, whose sum is σ = 1661057837400. Its totient is φ = 1661057837398.

The previous prime is 1661057837393. The next prime is 1661057837437. The reversal of 1661057837399 is 9937387501661.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661057837399 is a prime.

It is a super-2 number, since 2×1661057837399² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661057837393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830528918699 + 830528918700.

It is an arithmetic number, because the mean of its divisors is an integer number (830528918700).

Almost surely, 2^{1661057837399} is an apocalyptic number.

1661057837399 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661057837399 is an equidigital number, since it uses as much as digits as its factorization.

1661057837399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51438240, while the sum is 65.

The spelling of 1661057837399 in words is "one trillion, six hundred sixty-one billion, fifty-seven million, eight hundred thirty-seven thousand, three hundred ninety-nine".