1021621221 has 8 divisors (see below), whose sum is σ = 1513512960. Its totient is φ = 681080796.

The previous prime is 1021621217. The next prime is 1021621247. The reversal of 1021621221 is 1221261201.

1021621221 is a `hidden beast` number, since 1 + 0 + 21 + 621 + 2 + 21 = 666.

It is not a de Polignac number, because 1021621221 - 2² = 1021621217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021621194 and 1021621203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021621261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18918885 + ... + 18918938.

It is an arithmetic number, because the mean of its divisors is an integer number (189189120).

Almost surely, 2^1021621221 is an apocalyptic number.

It is an amenable number.

1021621221 is a deficient number, since it is larger than the sum of its proper divisors (491891739).

1021621221 is an equidigital number, since it uses as much as digits as its factorization.

1021621221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37837832 (or 37837826 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 1021621221 is about 31962.8099672103. The cubic root of 1021621221 is about 1007.1557468182.

Adding to 1021621221 its reverse (1221261201), we get a palindrome (2242882422).

The spelling of 1021621221 in words is "one billion, twenty-one million, six hundred twenty-one thousand, two hundred twenty-one".