40641021 has 16 divisors (see below), whose sum is σ = 60955520. Its totient is φ = 27092556.

The previous prime is 40641017. The next prime is 40641037. The reversal of 40641021 is 12014604.

40641021 is a `hidden beast` number, since 4 + 0 + 641 + 0 + 21 = 666.

It is not a de Polignac number, because 40641021 - 2² = 40641017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40640985 and 40641003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40641001) 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, 7105 + ... + 11478.

It is an arithmetic number, because the mean of its divisors is an integer number (3809720).

Almost surely, 2^40641021 is an apocalyptic number.

It is an amenable number.

40641021 is a deficient number, since it is larger than the sum of its proper divisors (20314499).

40641021 is an frugal number, since it uses more digits than its factorization.

40641021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18604 (or 18586 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 40641021 is about 6375.0310587479. The cubic root of 40641021 is about 343.8124005286.

Adding to 40641021 its reverse (12014604), we get a palindrome (52655625).

The spelling of 40641021 in words is "forty million, six hundred forty-one thousand, twenty-one".