421520645 has 24 divisors (see below), whose sum is σ = 625982976. Its totient is φ = 266804928.

The previous prime is 421520629. The next prime is 421520647. The reversal of 421520645 is 546025124.

It is not a de Polignac number, because 421520645 - 2⁴ = 421520629 is a prime.

It is a super-2 number, since 2×421520645² = 355359308322432050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421520647) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29717 + ... + 41546.

It is an arithmetic number, because the mean of its divisors is an integer number (26082624).

Almost surely, 2^421520645 is an apocalyptic number.

It is an amenable number.

421520645 is a deficient number, since it is larger than the sum of its proper divisors (204462331).

421520645 is a wasteful number, since it uses less digits than its factorization.

421520645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71301 (or 71288 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 421520645 is about 20530.9679508785. The cubic root of 421520645 is about 749.7899530310.

Adding to 421520645 its reverse (546025124), we get a palindrome (967545769).

The spelling of 421520645 in words is "four hundred twenty-one million, five hundred twenty thousand, six hundred forty-five".