621403 has 4 divisors (see below), whose sum is σ = 623968. Its totient is φ = 618840.

The previous prime is 621389. The next prime is 621419. The reversal of 621403 is 304126.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 304126 = 2 ⋅152063.

It is a cyclic number.

It is not a de Polignac number, because 621403 - 2⁵ = 621371 is a prime.

It is a super-2 number, since 2×621403² = 772283376818, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 876 + ... + 1417.

It is an arithmetic number, because the mean of its divisors is an integer number (155992).

2⁶²¹⁴⁰³ is an apocalyptic number.

621403 is a deficient number, since it is larger than the sum of its proper divisors (2565).

621403 is a wasteful number, since it uses less digits than its factorization.

621403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2564.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 621403 is about 788.2911898531. The cubic root of 621403 is about 85.3344607734.

Adding to 621403 its reverse (304126), we get a palindrome (925529).

It can be divided in two parts, 621 and 403, that added together give a 10-th power (1024 = 2¹⁰).

The spelling of 621403 in words is "six hundred twenty-one thousand, four hundred three".