420721642 has 8 divisors (see below), whose sum is σ = 688453632. Its totient is φ = 191237100.

The previous prime is 420721619. The next prime is 420721669. The reversal of 420721642 is 246127024.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 420721642.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9561834 + ... + 9561877.

It is an arithmetic number, because the mean of its divisors is an integer number (86056704).

Almost surely, 2^420721642 is an apocalyptic number.

420721642 is a deficient number, since it is larger than the sum of its proper divisors (267731990).

420721642 is a wasteful number, since it uses less digits than its factorization.

420721642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19123724.

The product of its (nonzero) digits is 5376, while the sum is 28.

The square root of 420721642 is about 20511.5002376715. The cubic root of 420721642 is about 749.3159048007.

Adding to 420721642 its reverse (246127024), we get a palindrome (666848666).

The spelling of 420721642 in words is "four hundred twenty million, seven hundred twenty-one thousand, six hundred forty-two".