243906390 has 192 divisors, whose sum is σ = 810141696. Its totient is φ = 51414912.

The previous prime is 243906379. The next prime is 243906391. The reversal of 243906390 is 93609342.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243906391) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 220579 + ... + 221681.

It is an arithmetic number, because the mean of its divisors is an integer number (4219488).

Almost surely, 2^243906390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 243906390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (405070848).

243906390 is an abundant number, since it is smaller than the sum of its proper divisors (566235306).

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

243906390 is a wasteful number, since it uses less digits than its factorization.

243906390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1145 (or 1133 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 36.

The square root of 243906390 is about 15617.5026812868. The cubic root of 243906390 is about 624.8000555090.

The spelling of 243906390 in words is "two hundred forty-three million, nine hundred six thousand, three hundred ninety".