613621 has 4 divisors (see below), whose sum is σ = 615244. Its totient is φ = 612000.

The previous prime is 613609. The next prime is 613633. The reversal of 613621 is 126316.

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

It is an interprime number because it is at equal distance from previous prime (613609) and next prime (613633).

It can be written as a sum of positive squares in 2 ways, for example, as 442225 + 171396 = 665^2 + 414^2 .

It is a cyclic number.

It is not a de Polignac number, because 613621 - 2⁷ = 613493 is a prime.

It is a Duffinian number.

613621 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (613651) 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, 91 + ... + 1111.

It is an arithmetic number, because the mean of its divisors is an integer number (153811).

2⁶¹³⁶²¹ is an apocalyptic number.

It is an amenable number.

613621 is a deficient number, since it is larger than the sum of its proper divisors (1623).

613621 is a wasteful number, since it uses less digits than its factorization.

613621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1622.

The product of its digits is 216, while the sum is 19.

The square root of 613621 is about 783.3396453646. The cubic root of 613621 is about 84.9767410410.

Adding to 613621 its reverse (126316), we get a palindrome (739937).

The spelling of 613621 in words is "six hundred thirteen thousand, six hundred twenty-one".