3818854647721 has 9 divisors (see below), whose sum is σ = 3876836110749. Its totient is φ = 3761727840684.

The previous prime is 3818854647697. The next prime is 3818854647737. The reversal of 3818854647721 is 1277464588183.

The square root of 3818854647721 is 1954189.

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

It is not a de Polignac number, because 3818854647721 - 2⁵ = 3818854647689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3818854647221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 130916080 + ... + 130945246.

It is an arithmetic number, because the mean of its divisors is an integer number (430759567861).

Almost surely, 2^{3818854647721} is an apocalyptic number.

3818854647721 is the 1954189-th square number.

3818854647721 is the 977095-th centered octagonal number.

It is an amenable number.

3818854647721 is a deficient number, since it is larger than the sum of its proper divisors (57981463028).

3818854647721 is an frugal number, since it uses more digits than its factorization.

3818854647721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58468 (or 29234 counting only the distinct ones).

The product of its digits is 72253440, while the sum is 64.

Multiplying 3818854647721 by its sum of digits (64), we get a square (244406697454144 = 15633512²).

The spelling of 3818854647721 in words is "three trillion, eight hundred eighteen billion, eight hundred fifty-four million, six hundred forty-seven thousand, seven hundred twenty-one".