3816891961 has 3 divisors (see below), whose sum is σ = 3816953743. Its totient is φ = 3816830180.

The previous prime is 3816891919. The next prime is 3816891973. The reversal of 3816891961 is 1691986183.

The square root of 3816891961 is 61781.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 44475561 + 3772416400 = 6669^2 + 61420^2 .

It is not a de Polignac number, because 3816891961 - 2¹¹ = 3816889913 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3816891899 and 3816891908.

It is not an unprimeable number, because it can be changed into a prime (3816895961) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 30891 + ... + 92671.

Almost surely, 2^3816891961 is an apocalyptic number.

3816891961 is the 61781-st square number.

3816891961 is the 30891-st centered octagonal number.

It is an amenable number.

3816891961 is a deficient number, since it is larger than the sum of its proper divisors (61782).

3816891961 is an frugal number, since it uses more digits than its factorization.

3816891961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123562 (or 61781 counting only the distinct ones).

The product of its digits is 559872, while the sum is 52.

The cubic root of 3816891961 is about 1562.7995916282.

The spelling of 3816891961 in words is "three billion, eight hundred sixteen million, eight hundred ninety-one thousand, nine hundred sixty-one".