621543643 has 16 divisors (see below), whose sum is σ = 717454080. Its totient is φ = 527436000.

The previous prime is 621543623. The next prime is 621543653. The reversal of 621543643 is 346345126.

It is not a de Polignac number, because 621543643 - 2¹³ = 621535451 is a prime.

It is a super-2 number, since 2×621543643² = 772633000307422898, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 621543599 and 621543608.

It is not an unprimeable number, because it can be changed into a prime (621543623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 477093 + ... + 478393.

It is an arithmetic number, because the mean of its divisors is an integer number (44840880).

Almost surely, 2^621543643 is an apocalyptic number.

621543643 is a deficient number, since it is larger than the sum of its proper divisors (95910437).

621543643 is a wasteful number, since it uses less digits than its factorization.

621543643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1938.

The product of its digits is 51840, while the sum is 34.

The square root of 621543643 is about 24930.7770235907. Note that the first 3 decimals coincide. The cubic root of 621543643 is about 853.4089824325.

Adding to 621543643 its reverse (346345126), we get a palindrome (967888769).

The spelling of 621543643 in words is "six hundred twenty-one million, five hundred forty-three thousand, six hundred forty-three".