420646581 has 16 divisors (see below), whose sum is σ = 627734400. Its totient is φ = 278381664.

The previous prime is 420646571. The next prime is 420646591. The reversal of 420646581 is 185646024.

420646581 is a `hidden beast` number, since 4 + 2 + 0 + 646 + 5 + 8 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (420646571) and next prime (420646591).

It is not a de Polignac number, because 420646581 - 2¹⁰ = 420645557 is a prime.

It is a super-2 number, since 2×420646581² = 353887092213979122, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420646571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53161 + ... + 60558.

It is an arithmetic number, because the mean of its divisors is an integer number (39233400).

Almost surely, 2^420646581 is an apocalyptic number.

It is an amenable number.

420646581 is a deficient number, since it is larger than the sum of its proper divisors (207087819).

420646581 is a wasteful number, since it uses less digits than its factorization.

420646581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113865 (or 113859 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 420646581 is about 20509.6704264110. The cubic root of 420646581 is about 749.2713403027.

The spelling of 420646581 in words is "four hundred twenty million, six hundred forty-six thousand, five hundred eighty-one".