20415021 has 8 divisors (see below), whose sum is σ = 29694624. Its totient is φ = 12372720.

The previous prime is 20415013. The next prime is 20415037. The reversal of 20415021 is 12051402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20415021 - 2³ = 20415013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20415041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 309286 + ... + 309351.

It is an arithmetic number, because the mean of its divisors is an integer number (3711828).

Almost surely, 2^20415021 is an apocalyptic number.

It is an amenable number.

20415021 is a deficient number, since it is larger than the sum of its proper divisors (9279603).

20415021 is a wasteful number, since it uses less digits than its factorization.

20415021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618651.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 20415021 is about 4518.2984629172. The cubic root of 20415021 is about 273.3064893659.

Adding to 20415021 its reverse (12051402), we get a palindrome (32466423).

It can be divided in two parts, 204 and 15021, that added together give a triangular number (15225 = T₁₇₄).

The spelling of 20415021 in words is "twenty million, four hundred fifteen thousand, twenty-one".