20015305421 has 16 divisors (see below), whose sum is σ = 20999030976. Its totient is φ = 19060080000.

The previous prime is 20015305369. The next prime is 20015305477. The reversal of 20015305421 is 12450351002.

It is a de Polignac number, because none of the positive numbers 2^k-20015305421 is a prime.

It is a super-2 number, since 2×20015305421² (a number of 21 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 (20015305721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 297086 + ... + 358176.

It is an arithmetic number, because the mean of its divisors is an integer number (1312439436).

Almost surely, 2^20015305421 is an apocalyptic number.

It is an amenable number.

20015305421 is a deficient number, since it is larger than the sum of its proper divisors (983725555).

20015305421 is a wasteful number, since it uses less digits than its factorization.

20015305421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61324.

The product of its (nonzero) digits is 1200, while the sum is 23.

Adding to 20015305421 its reverse (12450351002), we get a palindrome (32465656423).

The spelling of 20015305421 in words is "twenty billion, fifteen million, three hundred five thousand, four hundred twenty-one".