40015621 has 6 divisors (see below), whose sum is σ = 41443922. Its totient is φ = 38634960.

The previous prime is 40015609. The next prime is 40015627. The reversal of 40015621 is 12651004.

It can be written as a sum of positive squares in 3 ways, for example, as 10432900 + 29582721 = 3230^2 + 5439^2 .

It is not a de Polignac number, because 40015621 - 2²¹ = 37918469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40015627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 22950 + ... + 24631.

Almost surely, 2^40015621 is an apocalyptic number.

It is an amenable number.

40015621 is a deficient number, since it is larger than the sum of its proper divisors (1428301).

40015621 is an equidigital number, since it uses as much as digits as its factorization.

40015621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47639 (or 47610 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 40015621 is about 6325.7901482740. The cubic root of 40015621 is about 342.0397027651.

Adding to 40015621 its reverse (12651004), we get a palindrome (52666625).

The spelling of 40015621 in words is "forty million, fifteen thousand, six hundred twenty-one".