3953821 has 4 divisors (see below), whose sum is σ = 3965500. Its totient is φ = 3942144.

The previous prime is 3953819. The next prime is 3953827. The reversal of 3953821 is 1283593.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1283593 = 43 ⋅29851.

It can be written as a sum of positive squares in 2 ways, for example, as 2160900 + 1792921 = 1470^2 + 1339^2 .

It is a cyclic number.

It is not a de Polignac number, because 3953821 - 2¹ = 3953819 is a prime.

It is a d-powerful number, because it can be written as 3¹¹ + 9⁴ + 5⁷ + 3¹³ + 8³ + 2²¹ + 1 .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3953827) 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, 5316 + ... + 6013.

It is an arithmetic number, because the mean of its divisors is an integer number (991375).

Almost surely, 2^3953821 is an apocalyptic number.

It is an amenable number.

3953821 is a deficient number, since it is larger than the sum of its proper divisors (11679).

3953821 is a wasteful number, since it uses less digits than its factorization.

3953821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11678.

The product of its digits is 6480, while the sum is 31.

The square root of 3953821 is about 1988.4217359504. The cubic root of 3953821 is about 158.1268676059.

It can be divided in two parts, 3953 and 821, that added together give a palindrome (4774).

The spelling of 3953821 in words is "three million, nine hundred fifty-three thousand, eight hundred twenty-one".