621240 has 64 divisors (see below), whose sum is σ = 1935360. Its totient is φ = 159360.

The previous prime is 621239. The next prime is 621241. The reversal of 621240 is 42126.

It is an interprime number because it is at equal distance from previous prime (621239) and next prime (621241).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621241) 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, 3637 + ... + 3803.

It is an arithmetic number, because the mean of its divisors is an integer number (30240).

2⁶²¹²⁴⁰ is an apocalyptic number.

621240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (967680).

621240 is an abundant number, since it is smaller than the sum of its proper divisors (1314120).

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

621240 is a wasteful number, since it uses less digits than its factorization.

621240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 208 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 621240 is about 788.1877948814. The cubic root of 621240 is about 85.3269987702.

Adding to 621240 its reverse (42126), we get a palindrome (663366).

It can be divided in two parts, 621 and 240, that added together give a triangular number (861 = T₄₁).

The spelling of 621240 in words is "six hundred twenty-one thousand, two hundred forty".