6420720 has 80 divisors (see below), whose sum is σ = 20570112. Its totient is φ = 1655040.

The previous prime is 6420709. The next prime is 6420731. The reversal of 6420720 is 270246.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (6420709) and next prime (6420731).

It is a tau number, because it is divible by the number of its divisors (80).

It is a zygodrome in base 2.

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, 7009 + ... + 7871.

Almost surely, 2^6420720 is an apocalyptic number.

6420720 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 6420720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10285056).

6420720 is an abundant number, since it is smaller than the sum of its proper divisors (14149392).

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

6420720 is a wasteful number, since it uses less digits than its factorization.

6420720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910 (or 904 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 6420720 is about 2533.9139685475. The cubic root of 6420720 is about 185.8636994267.

Adding to 6420720 its reverse (270246), we get a palindrome (6690966).

It can be divided in two parts, 6420 and 720, that added together give a triangular number (7140 = T₁₁₉).

The spelling of 6420720 in words is "six million, four hundred twenty thousand, seven hundred twenty".