3921101021 has 2 divisors, whose sum is σ = 3921101022. Its totient is φ = 3921101020.

The previous prime is 3921100993. The next prime is 3921101029. The reversal of 3921101021 is 1201011293.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3362724121 + 558376900 = 57989^2 + 23630^2 .

It is an emirp because it is prime and its reverse (1201011293) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3921101021 - 2⁶ = 3921100957 is a prime.

It is a super-4 number, since 4×3921101021⁴ (a number of 39 digits) contains 4444 as substring. Note that it is a super-d number also for d = 3.

It is a junction number, because it is equal to n+sod(n) for n = 3921100984 and 3921101002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3921101029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1960550510 + 1960550511.

It is an arithmetic number, because the mean of its divisors is an integer number (1960550511).

Almost surely, 2^3921101021 is an apocalyptic number.

It is an amenable number.

3921101021 is a deficient number, since it is larger than the sum of its proper divisors (1).

3921101021 is an equidigital number, since it uses as much as digits as its factorization.

3921101021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 3921101021 is about 62618.6954591039. The cubic root of 3921101021 is about 1576.8946405365.

The spelling of 3921101021 in words is "three billion, nine hundred twenty-one million, one hundred one thousand, twenty-one".