621522 has 48 divisors (see below), whose sum is σ = 1523808. Its totient is φ = 181440.

The previous prime is 621521. The next prime is 621527. The reversal of 621522 is 225126.

621522 is nontrivially palindromic in base 8 and base 15.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 621495 and 621504.

It is not an unprimeable number, because it can be changed into a prime (621521) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8478 + ... + 8550.

It is an arithmetic number, because the mean of its divisors is an integer number (31746).

2⁶²¹⁵²² is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621522, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (761904).

621522 is an abundant number, since it is smaller than the sum of its proper divisors (902286).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

621522 is a wasteful number, since it uses less digits than its factorization.

621522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 132 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 621522 is about 788.3666659620. The cubic root of 621522 is about 85.3399076695.

Adding to 621522 its reverse (225126), we get a palindrome (846648).

It can be divided in two parts, 6 and 21522, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 621522 in words is "six hundred twenty-one thousand, five hundred twenty-two".