620621640 has 96 divisors (see below), whose sum is σ = 2028499200. Its totient is φ = 164557440.

The previous prime is 620621597. The next prime is 620621647. The reversal of 620621640 is 46126026.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (620621647) 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, 59625 + ... + 69255.

It is an arithmetic number, because the mean of its divisors is an integer number (21130200).

Almost surely, 2^620621640 is an apocalyptic number.

620621640 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 620621640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1014249600).

620621640 is an abundant number, since it is smaller than the sum of its proper divisors (1407877560).

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

620621640 is a wasteful number, since it uses less digits than its factorization.

620621640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9827 (or 9820 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 620621640 is about 24912.2789001729. The cubic root of 620621640 is about 852.9867889454.

Adding to 620621640 its reverse (46126026), we get a palindrome (666747666).

The spelling of 620621640 in words is "six hundred twenty million, six hundred twenty-one thousand, six hundred forty".