3916371821 has 4 divisors (see below), whose sum is σ = 4146746652. Its totient is φ = 3685996992.

The previous prime is 3916371769. The next prime is 3916371829. The reversal of 3916371821 is 1281736193.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1281736193 = 3511 ⋅365063.

It can be written as a sum of positive squares in 2 ways, for example, as 1490809321 + 2425562500 = 38611^2 + 49250^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3916371821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3916371829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115187390 + ... + 115187423.

It is an arithmetic number, because the mean of its divisors is an integer number (1036686663).

Almost surely, 2^3916371821 is an apocalyptic number.

It is an amenable number.

3916371821 is a deficient number, since it is larger than the sum of its proper divisors (230374831).

3916371821 is a wasteful number, since it uses less digits than its factorization.

3916371821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230374830.

The product of its digits is 54432, while the sum is 41.

The square root of 3916371821 is about 62580.9221808052. The cubic root of 3916371821 is about 1576.2604266407.

The spelling of 3916371821 in words is "three billion, nine hundred sixteen million, three hundred seventy-one thousand, eight hundred twenty-one".