3981564 has 36 divisors (see below), whose sum is σ = 10596040. Its totient is φ = 1257120.

The previous prime is 3981563. The next prime is 3981569. The reversal of 3981564 is 4651893.

3981564 is a `hidden beast` number, since 3 + 98 + 1 + 564 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

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

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

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3981563) 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, 2227 + ... + 3594.

Almost surely, 2^3981564 is an apocalyptic number.

It is an amenable number.

3981564 is an abundant number, since it is smaller than the sum of its proper divisors (6614476).

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

3981564 is a wasteful number, since it uses less digits than its factorization.

3981564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5850 (or 5845 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 3981564 is about 1995.3856770058. The cubic root of 3981564 is about 158.4958518421.

The spelling of 3981564 in words is "three million, nine hundred eighty-one thousand, five hundred sixty-four".