6420061620 has 480 divisors, whose sum is σ = 24588748800. Its totient is φ = 1369633536.

The previous prime is 6420061619. The next prime is 6420061621. The reversal of 6420061620 is 261600246.

It is a happy number.

6420061620 is a `hidden beast` number, since 6 + 4 + 20 + 0 + 616 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (6420061619) and next prime (6420061621).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6420061621) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 17883001 + ... + 17883359.

It is an arithmetic number, because the mean of its divisors is an integer number (51226560).

Almost surely, 2^6420061620 is an apocalyptic number.

6420061620 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 6420061620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12294374400).

6420061620 is an abundant number, since it is smaller than the sum of its proper divisors (18168687180).

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

6420061620 is a wasteful number, since it uses less digits than its factorization.

6420061620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489 (or 478 counting only the distinct ones).

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

The square root of 6420061620 is about 80125.2870197667. The cubic root of 6420061620 is about 1858.5734639433.

Adding to 6420061620 its reverse (261600246), we get a palindrome (6681661866).

The spelling of 6420061620 in words is "six billion, four hundred twenty million, sixty-one thousand, six hundred twenty".