20515021420 has 24 divisors (see below), whose sum is σ = 43090034400. Its totient is φ = 8204391552.

The previous prime is 20515021381. The next prime is 20515021421. The reversal of 20515021420 is 2412051502.

It is a super-2 number, since 2×20515021420² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20515021391 and 20515021400.

It is not an unprimeable number, because it can be changed into a prime (20515021421) 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, 5721 + ... + 202639.

It is an arithmetic number, because the mean of its divisors is an integer number (1795418100).

Almost surely, 2^20515021420 is an apocalyptic number.

20515021420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20515021420 is an abundant number, since it is smaller than the sum of its proper divisors (22575012980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20515021420 is a wasteful number, since it uses less digits than its factorization.

20515021420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202137 (or 202135 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 22.

Adding to 20515021420 its reverse (2412051502), we get a palindrome (22927072922).

The spelling of 20515021420 in words is "twenty billion, five hundred fifteen million, twenty-one thousand, four hundred twenty".