2021401221 has 16 divisors (see below), whose sum is σ = 3179593728. Its totient is φ = 1117825200.

The previous prime is 2021401157. The next prime is 2021401223. The reversal of 2021401221 is 1221041202.

It is not a de Polignac number, because 2021401221 - 2⁶ = 2021401157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2021401221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021401223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1551885 + ... + 1553186.

It is an arithmetic number, because the mean of its divisors is an integer number (198724608).

Almost surely, 2^2021401221 is an apocalyptic number.

2021401221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2021401221 is a deficient number, since it is larger than the sum of its proper divisors (1158192507).

2021401221 is a wasteful number, since it uses less digits than its factorization.

2021401221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3105112.

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 2021401221 is about 44959.9957851422. The cubic root of 2021401221 is about 1264.3990898924.

Adding to 2021401221 its reverse (1221041202), we get a palindrome (3242442423).

The spelling of 2021401221 in words is "two billion, twenty-one million, four hundred one thousand, two hundred twenty-one".