20015421 has 8 divisors (see below), whose sum is σ = 27338304. Its totient is φ = 13018080.

The previous prime is 20015419. The next prime is 20015431. The reversal of 20015421 is 12451002.

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

It is not a de Polignac number, because 20015421 - 2¹ = 20015419 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20015421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20015431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81241 + ... + 81486.

It is an arithmetic number, because the mean of its divisors is an integer number (3417288).

Almost surely, 2^20015421 is an apocalyptic number.

It is an amenable number.

20015421 is a deficient number, since it is larger than the sum of its proper divisors (7322883).

20015421 is a wasteful number, since it uses less digits than its factorization.

20015421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162771.

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

The square root of 20015421 is about 4473.8597429960. The cubic root of 20015421 is about 271.5115087932.

Adding to 20015421 its reverse (12451002), we get a palindrome (32466423).

The spelling of 20015421 in words is "twenty million, fifteen thousand, four hundred twenty-one".