4021217381 has 2 divisors, whose sum is σ = 4021217382. Its totient is φ = 4021217380.

The previous prime is 4021217377. The next prime is 4021217419. The reversal of 4021217381 is 1837121204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3132640900 + 888576481 = 55970^2 + 29809^2 .

It is a cyclic number.

It is not a de Polignac number, because 4021217381 - 2² = 4021217377 is a prime.

It is a super-2 number, since 2×4021217381² = 32340378450512998322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4021217371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2010608690 + 2010608691.

It is an arithmetic number, because the mean of its divisors is an integer number (2010608691).

Almost surely, 2^4021217381 is an apocalyptic number.

It is an amenable number.

4021217381 is a deficient number, since it is larger than the sum of its proper divisors (1).

4021217381 is an equidigital number, since it uses as much as digits as its factorization.

4021217381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 4021217381 is about 63413.0694809832. The cubic root of 4021217381 is about 1590.2028117017.

Adding to 4021217381 its reverse (1837121204), we get a palindrome (5858338585).

The spelling of 4021217381 in words is "four billion, twenty-one million, two hundred seventeen thousand, three hundred eighty-one".