2021421620 has 12 divisors (see below), whose sum is σ = 4244985444. Its totient is φ = 808568640.

The previous prime is 2021421613. The next prime is 2021421641. The reversal of 2021421620 is 261241202.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 695587876 + 1325833744 = 26374^2 + 36412^2 .

It is a super-2 number, since 2×2021421620² = 8172290731606848800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 101071081 = 2021421620 / (2 + 0 + 2 + 1 + 4 + 2 + 1 + 6 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 2021421592 and 2021421601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50535521 + ... + 50535560.

It is an arithmetic number, because the mean of its divisors is an integer number (353748787).

Almost surely, 2^2021421620 is an apocalyptic number.

2021421620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2021421620 is an abundant number, since it is smaller than the sum of its proper divisors (2223563824).

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

2021421620 is a wasteful number, since it uses less digits than its factorization.

2021421620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101071090 (or 101071088 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 2021421620 is about 44960.2226417975. Note that the first 3 decimals coincide. The cubic root of 2021421620 is about 1264.4033431121.

Adding to 2021421620 its reverse (261241202), we get a palindrome (2282662822).

The spelling of 2021421620 in words is "two billion, twenty-one million, four hundred twenty-one thousand, six hundred twenty".