3912821 has 8 divisors (see below), whose sum is σ = 4341600. Its totient is φ = 3496240.

The previous prime is 3912817. The next prime is 3912823. The reversal of 3912821 is 1282193.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 3912821 - 2² = 3912817 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 (3912823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2366 + ... + 3663.

It is an arithmetic number, because the mean of its divisors is an integer number (542700).

Almost surely, 2^3912821 is an apocalyptic number.

It is an amenable number.

3912821 is a deficient number, since it is larger than the sum of its proper divisors (428779).

3912821 is a wasteful number, since it uses less digits than its factorization.

3912821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6099.

The product of its digits is 864, while the sum is 26.

The square root of 3912821 is about 1978.0851852233. The cubic root of 3912821 is about 157.5783904725.

It can be divided in two parts, 391 and 2821, that multiplied together give a palindrome (1103011).

The spelling of 3912821 in words is "three million, nine hundred twelve thousand, eight hundred twenty-one".