405342720 has 240 divisors, whose sum is σ = 1428950952. Its totient is φ = 106168320.

The previous prime is 405342709. The next prime is 405342761. The reversal of 405342720 is 27243504.

It can be written as a sum of positive squares in 4 ways, for example, as 370485504 + 34857216 = 19248^2 + 5904^2 .

It is a tau number, because it is divible by the number of its divisors (240).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1681800 + ... + 1682040.

Almost surely, 2^405342720 is an apocalyptic number.

405342720 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 405342720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (714475476).

405342720 is an abundant number, since it is smaller than the sum of its proper divisors (1023608232).

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

405342720 is a wasteful number, since it uses less digits than its factorization.

405342720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343 (or 324 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 27.

The square root of 405342720 is about 20133.1249437339. The cubic root of 405342720 is about 740.0722598052.

The spelling of 405342720 in words is "four hundred five million, three hundred forty-two thousand, seven hundred twenty".