620645 has 8 divisors (see below), whose sum is σ = 752760. Its totient is φ = 491200.

The previous prime is 620639. The next prime is 620647. The reversal of 620645 is 546026.

620645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 410881 + 209764 = 641^2 + 458^2 .

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

It is not a de Polignac number, because 620645 - 2¹⁰ = 619621 is a prime.

It is a Curzon number.

It is a plaindrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 620645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (620647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110 + ... + 1119.

It is an arithmetic number, because the mean of its divisors is an integer number (94095).

2⁶²⁰⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

620645 is a deficient number, since it is larger than the sum of its proper divisors (132115).

620645 is a wasteful number, since it uses less digits than its factorization.

620645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1335.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 620645 is about 787.8102563435. The cubic root of 620645 is about 85.2997490861.

The spelling of 620645 in words is "six hundred twenty thousand, six hundred forty-five".