420721646 has 16 divisors (see below), whose sum is σ = 657538560. Its totient is φ = 201669240.

The previous prime is 420721619. The next prime is 420721669. The reversal of 420721646 is 646127024.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25076 + ... + 38343.

It is an arithmetic number, because the mean of its divisors is an integer number (41096160).

Almost surely, 2^420721646 is an apocalyptic number.

420721646 is a deficient number, since it is larger than the sum of its proper divisors (236816914).

420721646 is a wasteful number, since it uses less digits than its factorization.

420721646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63559.

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 420721646 is about 20511.5003351778. The cubic root of 420721646 is about 749.3159071754.

The spelling of 420721646 in words is "four hundred twenty million, seven hundred twenty-one thousand, six hundred forty-six".