1999356424657 has 2 divisors, whose sum is σ = 1999356424658. Its totient is φ = 1999356424656.

The previous prime is 1999356424607. The next prime is 1999356424717. The reversal of 1999356424657 is 7564246539991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1051918948161 + 947437476496 = 1025631^2 + 973364^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999356424657 - 2¹⁵ = 1999356391889 is a prime.

It is a super-2 number, since 2×1999356424657² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1999356424607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999678212328 + 999678212329.

It is an arithmetic number, because the mean of its divisors is an integer number (999678212329).

Almost surely, 2^{1999356424657} is an apocalyptic number.

It is an amenable number.

1999356424657 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999356424657 is an equidigital number, since it uses as much as digits as its factorization.

1999356424657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 440899200, while the sum is 70.

The spelling of 1999356424657 in words is "one trillion, nine hundred ninety-nine billion, three hundred fifty-six million, four hundred twenty-four thousand, six hundred fifty-seven".