2021264640 has 216 divisors, whose sum is σ = 7405456968. Its totient is φ = 507248640.

The previous prime is 2021264639. The next prime is 2021264653. The reversal of 2021264640 is 464621202.

2021264640 is a `hidden beast` number, since 2 + 0 + 2 + 12 + 6 + 4 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 464488704 + 1556775936 = 21552^2 + 39456^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 190680 + ... + 201000.

It is an arithmetic number, because the mean of its divisors is an integer number (34284523).

Almost surely, 2^2021264640 is an apocalyptic number.

2021264640 is a gapful number since it is divisible by the number (20) 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 2021264640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3702728484).

2021264640 is an abundant number, since it is smaller than the sum of its proper divisors (5384192328).

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

2021264640 is a wasteful number, since it uses less digits than its factorization.

2021264640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10365 (or 10348 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 2021264640 is about 44958.4768425266. The cubic root of 2021264640 is about 1264.3706118281.

Adding to 2021264640 its reverse (464621202), we get a palindrome (2485885842).

The spelling of 2021264640 in words is "two billion, twenty-one million, two hundred sixty-four thousand, six hundred forty".