420725581 has 4 divisors (see below), whose sum is σ = 420797052. Its totient is φ = 420654112.

The previous prime is 420725579. The next prime is 420725587. The reversal of 420725581 is 185527024.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62948356 + 357777225 = 7934^2 + 18915^2 .

It is a cyclic number.

It is not a de Polignac number, because 420725581 - 2¹ = 420725579 is a prime.

It is a super-2 number, since 2×420725581² = 354020029015575122, 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 (420725587) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26026 + ... + 38971.

It is an arithmetic number, because the mean of its divisors is an integer number (105199263).

Almost surely, 2^420725581 is an apocalyptic number.

It is an amenable number.

420725581 is a deficient number, since it is larger than the sum of its proper divisors (71471).

420725581 is an equidigital number, since it uses as much as digits as its factorization.

420725581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71470.

The product of its (nonzero) digits is 22400, while the sum is 34.

The square root of 420725581 is about 20511.5962567519. The cubic root of 420725581 is about 749.3182432796.

The spelling of 420725581 in words is "four hundred twenty million, seven hundred twenty-five thousand, five hundred eighty-one".