3691797821 has 2 divisors, whose sum is σ = 3691797822. Its totient is φ = 3691797820.

The previous prime is 3691797761. The next prime is 3691797841. The reversal of 3691797821 is 1287971963.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3679756921 + 12040900 = 60661^2 + 3470^2 .

It is a cyclic number.

It is not a de Polignac number, because 3691797821 - 2¹⁴ = 3691781437 is a prime.

It is a super-2 number, since 2×3691797821² = 27258742302280696082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3691797841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1845898910 + 1845898911.

It is an arithmetic number, because the mean of its divisors is an integer number (1845898911).

Almost surely, 2^3691797821 is an apocalyptic number.

It is an amenable number.

3691797821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3691797821 is an equidigital number, since it uses as much as digits as its factorization.

3691797821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1143072, while the sum is 53.

The square root of 3691797821 is about 60760.1664003646. The cubic root of 3691797821 is about 1545.5366318726.

The spelling of 3691797821 in words is "three billion, six hundred ninety-one million, seven hundred ninety-seven thousand, eight hundred twenty-one".