2640220420 has 24 divisors (see below), whose sum is σ = 5679695448. Its totient is φ = 1030329600.

The previous prime is 2640220397. The next prime is 2640220469. The reversal of 2640220420 is 240220462.

It can be written as a sum of positive squares in 4 ways, for example, as 347151424 + 2293068996 = 18632^2 + 47886^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2640220391 and 2640220400.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1609071 + ... + 1610710.

It is an arithmetic number, because the mean of its divisors is an integer number (236653977).

Almost surely, 2^2640220420 is an apocalyptic number.

2640220420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2640220420 is an abundant number, since it is smaller than the sum of its proper divisors (3039475028).

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

2640220420 is a wasteful number, since it uses less digits than its factorization.

2640220420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3219831 (or 3219829 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 2640220420 is about 51383.0752291063. The cubic root of 2640220420 is about 1382.1231094643.

Adding to 2640220420 its reverse (240220462), we get a palindrome (2880440882).

The spelling of 2640220420 in words is "two billion, six hundred forty million, two hundred twenty thousand, four hundred twenty".