423990 has 48 divisors (see below), whose sum is σ = 1261728. Its totient is φ = 96768.

The previous prime is 423989. The next prime is 423991. The reversal of 423990 is 99324.

It is an interprime number because it is at equal distance from previous prime (423989) and next prime (423991).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (423991) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 294 + ... + 966.

It is an arithmetic number, because the mean of its divisors is an integer number (26286).

2⁴²³⁹⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 423990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (630864).

423990 is an abundant number, since it is smaller than the sum of its proper divisors (837738).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

423990 is a wasteful number, since it uses less digits than its factorization.

423990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 693 (or 690 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 423990 is about 651.1451451098. The cubic root of 423990 is about 75.1251244688.

The spelling of 423990 in words is "four hundred twenty-three thousand, nine hundred ninety".