3972816 has 60 divisors (see below), whose sum is σ = 11374272. Its totient is φ = 1293888.

The previous prime is 3972811. The next prime is 3972817. The reversal of 3972816 is 6182793.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (18144) is a multiple of the sum of its prime factors (648).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3972811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6475 + ... + 7061.

Almost surely, 2^3972816 is an apocalyptic number.

3972816 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3972816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5687136).

3972816 is an abundant number, since it is smaller than the sum of its proper divisors (7401456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3972816 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (3972815) it forms an eRAP, since the sums of their prime factors are consecutive (647 and 648).

3972816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648 (or 639 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 3972816 is about 1993.1924141939. The cubic root of 3972816 is about 158.3796882434.

The spelling of 3972816 in words is "three million, nine hundred seventy-two thousand, eight hundred sixteen".