20415463442021 has 4 divisors (see below), whose sum is σ = 20415663247500. Its totient is φ = 20415263636544.

The previous prime is 20415463441957. The next prime is 20415463442039. The reversal of 20415463442021 is 12024436451402.

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 17019131430625 + 3396332011396 = 4125425^2 + 1842914^2 .

It is a cyclic number.

It is not a de Polignac number, because 20415463442021 - 2⁶ = 20415463441957 is a prime.

It is a super-2 number, since 2×20415463442021² (a number of 27 digits) contains 22 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 (20415463442041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99749396 + ... + 99953853.

It is an arithmetic number, because the mean of its divisors is an integer number (5103915811875).

Almost surely, 2^{20415463442021} is an apocalyptic number.

It is an amenable number.

20415463442021 is a deficient number, since it is larger than the sum of its proper divisors (199805479).

20415463442021 is a wasteful number, since it uses less digits than its factorization.

20415463442021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199805478.

The product of its (nonzero) digits is 184320, while the sum is 38.

Adding to 20415463442021 its reverse (12024436451402), we get a palindrome (32439899893423).

The spelling of 20415463442021 in words is "twenty trillion, four hundred fifteen billion, four hundred sixty-three million, four hundred forty-two thousand, twenty-one".