425721 has 4 divisors (see below), whose sum is σ = 567632. Its totient is φ = 283812.

The previous prime is 425713. The next prime is 425779. The reversal of 425721 is 127524.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 425721 - 2³ = 425713 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (425701) 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, 70951 + ... + 70956.

It is an arithmetic number, because the mean of its divisors is an integer number (141908).

2⁴²⁵⁷²¹ is an apocalyptic number.

It is an amenable number.

425721 is a deficient number, since it is larger than the sum of its proper divisors (141911).

425721 is a wasteful number, since it uses less digits than its factorization.

425721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141910.

The product of its digits is 560, while the sum is 21.

The square root of 425721 is about 652.4729879466. The cubic root of 425721 is about 75.2272220180.

It can be divided in two parts, 4257 and 21, that added together give a triangular number (4278 = T₉₂).

The spelling of 425721 in words is "four hundred twenty-five thousand, seven hundred twenty-one".