199945757687405 has 4 divisors (see below), whose sum is σ = 239934909224892. Its totient is φ = 159956606149920.

The previous prime is 199945757687359. The next prime is 199945757687527. The reversal of 199945757687405 is 504786757549991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 118532473856644 + 81413283830761 = 10887262^2 + 9022931^2 .

It is not a de Polignac number, because 199945757687405 - 2⁸ = 199945757687149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19994575768736 + ... + 19994575768745.

It is an arithmetic number, because the mean of its divisors is an integer number (59983727306223).

Almost surely, 2^{199945757687405} is an apocalyptic number.

It is an amenable number.

199945757687405 is a deficient number, since it is larger than the sum of its proper divisors (39989151537487).

199945757687405 is an equidigital number, since it uses as much as digits as its factorization.

199945757687405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39989151537486.

The product of its (nonzero) digits is 24004512000, while the sum is 86.

The spelling of 199945757687405 in words is "one hundred ninety-nine trillion, nine hundred forty-five billion, seven hundred fifty-seven million, six hundred eighty-seven thousand, four hundred five".