21145502345420 has 48 divisors (see below), whose sum is σ = 44831159220960. Its totient is φ = 8377242510336.

The previous prime is 21145502345369. The next prime is 21145502345423. The reversal of 21145502345420 is 2454320554112.

It is not an unprimeable number, because it can be changed into a prime (21145502345423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 304310 + ... + 6510269.

It is an arithmetic number, because the mean of its divisors is an integer number (933982483770).

Almost surely, 2^{21145502345420} is an apocalyptic number.

21145502345420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21145502345420 is an abundant number, since it is smaller than the sum of its proper divisors (23685656875540).

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

21145502345420 is a wasteful number, since it uses less digits than its factorization.

21145502345420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6816074 (or 6816072 counting only the distinct ones).

The product of its (nonzero) digits is 192000, while the sum is 38.

Adding to 21145502345420 its reverse (2454320554112), we get a palindrome (23599822899532).

The spelling of 21145502345420 in words is "twenty-one trillion, one hundred forty-five billion, five hundred two million, three hundred forty-five thousand, four hundred twenty".