7720020 has 144 divisors (see below), whose sum is σ = 29248128. Its totient is φ = 1601280.

The previous prime is 7720001. The next prime is 7720021. The reversal of 7720020 is 200277.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 7719975 and 7720002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7720021) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13582 + ... + 14138.

It is an arithmetic number, because the mean of its divisors is an integer number (203112).

Almost surely, 2^7720020 is an apocalyptic number.

7720020 is a gapful number since it is divisible by the number (70) 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 7720020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14624064).

7720020 is an abundant number, since it is smaller than the sum of its proper divisors (21528108).

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

7720020 is a wasteful number, since it uses less digits than its factorization.

7720020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590 (or 585 counting only the distinct ones).

The product of its (nonzero) digits is 196, while the sum is 18.

The square root of 7720020 is about 2778.4923969664. The cubic root of 7720020 is about 197.6390731192.

Adding to 7720020 its reverse (200277), we get a palindrome (7920297).

It can be divided in two parts, 7 and 720020, that added together give a palindrome (720027).

The spelling of 7720020 in words is "seven million, seven hundred twenty thousand, twenty".