999993421 has 6 divisors (see below), whose sum is σ = 1163257710. Its totient is φ = 857137176.

The previous prime is 999993377. The next prime is 999993439. The reversal of 999993421 is 124399999.

It can be written as a sum of positive squares in only one way, i.e., 950797225 + 49196196 = 30835^2 + 7014^2 .

It is not a de Polignac number, because 999993421 - 2¹¹ = 999991373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999993461) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10203966 + ... + 10204063.

It is an arithmetic number, because the mean of its divisors is an integer number (193876285).

Almost surely, 2^999993421 is an apocalyptic number.

It is an amenable number.

999993421 is a deficient number, since it is larger than the sum of its proper divisors (163264289).

999993421 is a wasteful number, since it uses less digits than its factorization.

999993421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20408043 (or 20408036 counting only the distinct ones).

The product of its digits is 1417176, while the sum is 55.

The square root of 999993421 is about 31622.6725783891. The cubic root of 999993421 is about 999.9978069952.

The spelling of 999993421 in words is "nine hundred ninety-nine million, nine hundred ninety-three thousand, four hundred twenty-one".