40180821 has 4 divisors (see below), whose sum is σ = 53574432. Its totient is φ = 26787212.

The previous prime is 40180783. The next prime is 40180841. The reversal of 40180821 is 12808104.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40180821 - 2⁶ = 40180757 is a prime.

It is a super-2 number, since 2×40180821² = 3228996752468082, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 40180791 and 40180800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40180841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6696801 + ... + 6696806.

It is an arithmetic number, because the mean of its divisors is an integer number (13393608).

Almost surely, 2^40180821 is an apocalyptic number.

It is an amenable number.

40180821 is a deficient number, since it is larger than the sum of its proper divisors (13393611).

40180821 is a wasteful number, since it uses less digits than its factorization.

40180821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13393610.

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 40180821 is about 6338.8343565675. The cubic root of 40180821 is about 342.5097473561.

Adding to 40180821 its reverse (12808104), we get a palindrome (52988925).

The spelling of 40180821 in words is "forty million, one hundred eighty thousand, eight hundred twenty-one".