420728345 has 8 divisors (see below), whose sum is σ = 506306376. Its totient is φ = 335627776.

The previous prime is 420728339. The next prime is 420728389. The reversal of 420728345 is 543827024.

It can be written as a sum of positive squares in 4 ways, for example, as 1175056 + 419553289 = 1084^2 + 20483^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 420728345 - 2⁶ = 420728281 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117422 + ... + 120951.

It is an arithmetic number, because the mean of its divisors is an integer number (63288297).

Almost surely, 2^420728345 is an apocalyptic number.

It is an amenable number.

420728345 is a deficient number, since it is larger than the sum of its proper divisors (85578031).

420728345 is a wasteful number, since it uses less digits than its factorization.

420728345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238731.

The product of its (nonzero) digits is 53760, while the sum is 35.

The square root of 420728345 is about 20511.6636331625. The cubic root of 420728345 is about 749.3198841838.

The spelling of 420728345 in words is "four hundred twenty million, seven hundred twenty-eight thousand, three hundred forty-five".