21501200154120 has 64 divisors (see below), whose sum is σ = 64521172909440. Its totient is φ = 5732091379200.

The previous prime is 21501200154097. The next prime is 21501200154139. The reversal of 21501200154120 is 2145100210512.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23963821 + ... + 24844860.

It is an arithmetic number, because the mean of its divisors is an integer number (1008143326710).

Almost surely, 2^{21501200154120} is an apocalyptic number.

21501200154120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21501200154120 is an abundant number, since it is smaller than the sum of its proper divisors (43019972755320).

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

21501200154120 is a wasteful number, since it uses less digits than its factorization.

21501200154120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48812366 (or 48812362 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 24.

Adding to 21501200154120 its reverse (2145100210512), we get a palindrome (23646300364632).

The spelling of 21501200154120 in words is "twenty-one trillion, five hundred one billion, two hundred million, one hundred fifty-four thousand, one hundred twenty".