40550021 has 4 divisors (see below), whose sum is σ = 40638444. Its totient is φ = 40461600.

The previous prime is 40549997. The next prime is 40550023. The reversal of 40550021 is 12005504.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4669921 + 35880100 = 2161^2 + 5990^2 .

It is a cyclic number.

It is not a de Polignac number, because 40550021 - 2¹⁰ = 40548997 is a prime.

It is a super-3 number, since 3×40550021³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40550023) 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, 43520 + ... + 44441.

It is an arithmetic number, because the mean of its divisors is an integer number (10159611).

Almost surely, 2^40550021 is an apocalyptic number.

It is an amenable number.

40550021 is a deficient number, since it is larger than the sum of its proper divisors (88423).

40550021 is an equidigital number, since it uses as much as digits as its factorization.

40550021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88422.

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 40550021 is about 6367.8898388713. The cubic root of 40550021 is about 343.5555967011. Note that the first 4 decimals are identical.

Adding to 40550021 its reverse (12005504), we get a palindrome (52555525).

The spelling of 40550021 in words is "forty million, five hundred fifty thousand, twenty-one".