6420561240 has 64 divisors (see below), whose sum is σ = 19533000960. Its totient is φ = 1688032640.

The previous prime is 6420561229. The next prime is 6420561269. The reversal of 6420561240 is 421650246.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 6420561198 and 6420561207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 368274 + ... + 385313.

It is an arithmetic number, because the mean of its divisors is an integer number (305203140).

Almost surely, 2^6420561240 is an apocalyptic number.

6420561240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6420561240 is an abundant number, since it is smaller than the sum of its proper divisors (13112439720).

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

6420561240 is a wasteful number, since it uses less digits than its factorization.

6420561240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753672 (or 753668 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 6420561240 is about 80128.4047014540. The cubic root of 6420561240 is about 1858.6216751310.

The spelling of 6420561240 in words is "six billion, four hundred twenty million, five hundred sixty-one thousand, two hundred forty".