165819421089290 has 16 divisors (see below), whose sum is σ = 298932040603368. Its totient is φ = 66226194515136.

The previous prime is 165819421089233. The next prime is 165819421089323. The reversal of 165819421089290 is 92980124918561.

It can be written as a sum of positive squares in 4 ways, for example, as 90446585936281 + 75372835153009 = 9510341^2 + 8681753^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12696733217 + ... + 12696746276.

Almost surely, 2^{165819421089290} is an apocalyptic number.

165819421089290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

165819421089290 is a deficient number, since it is larger than the sum of its proper divisors (133112619514078).

165819421089290 is a wasteful number, since it uses less digits than its factorization.

165819421089290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25393480153.

The product of its (nonzero) digits is 22394880, while the sum is 65.

The spelling of 165819421089290 in words is "one hundred sixty-five trillion, eight hundred nineteen billion, four hundred twenty-one million, eighty-nine thousand, two hundred ninety".