40641 has 16 divisors (see below), whose sum is σ = 61440. Its totient is φ = 23760.

The previous prime is 40639. The next prime is 40693. The reversal of 40641 is 14604.

40641 = T₅₈ + T₅₉ + ... + T₇₅.

40641 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 40641 - 2¹ = 40639 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 40641.

It is not an unprimeable number, because it can be changed into a prime (40241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1296 + ... + 1326.

It is an arithmetic number, because the mean of its divisors is an integer number (3840).

2⁴⁰⁶⁴¹ is an apocalyptic number.

40641 is the 128-th centered pentagonal number.

It is an amenable number.

40641 is a deficient number, since it is larger than the sum of its proper divisors (20799).

40641 is a wasteful number, since it uses less digits than its factorization.

40641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 40641 is about 201.5961309153. The cubic root of 40641 is about 34.3812341310.

The spelling of 40641 in words is "forty thousand, six hundred forty-one".