1993890409 has 9 divisors (see below), whose sum is σ = 2319787197. Its totient is φ = 1708781004.

The previous prime is 1993890383. The next prime is 1993890439. The reversal of 1993890409 is 9040983991.

The square root of 1993890409 is 44653.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1993890409 - 2²⁷ = 1859672681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1993890439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 309382 + ... + 315760.

It is an arithmetic number, because the mean of its divisors is an integer number (257754133).

Almost surely, 2^1993890409 is an apocalyptic number.

1993890409 is the 44653-rd square number.

1993890409 is the 22327-th centered octagonal number.

It is an amenable number.

1993890409 is a deficient number, since it is larger than the sum of its proper divisors (325896788).

1993890409 is an frugal number, since it uses more digits than its factorization.

1993890409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12772 (or 6386 counting only the distinct ones).

The product of its (nonzero) digits is 629856, while the sum is 52.

The cubic root of 1993890409 is about 1258.6368075887.

The spelling of 1993890409 in words is "one billion, nine hundred ninety-three million, eight hundred ninety thousand, four hundred nine".