21354727753720 has 32 divisors (see below), whose sum is σ = 48063242459520. Its totient is φ = 8539205765760.

The previous prime is 21354727753627. The next prime is 21354727753727. The reversal of 21354727753720 is 2735772745312.

It is a happy number.

It is a Smith number, since the sum of its digits (55) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21354727753727) 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 7 ways as a sum of consecutive naturals, for example, 83787912 + ... + 84042391.

It is an arithmetic number, because the mean of its divisors is an integer number (1501976326860).

Almost surely, 2^{21354727753720} is an apocalyptic number.

21354727753720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21354727753720 is an abundant number, since it is smaller than the sum of its proper divisors (26708514705800).

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

21354727753720 is a wasteful number, since it uses less digits than its factorization.

21354727753720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167833495 (or 167833491 counting only the distinct ones).

The product of its (nonzero) digits is 17287200, while the sum is 55.

The spelling of 21354727753720 in words is "twenty-one trillion, three hundred fifty-four billion, seven hundred twenty-seven million, seven hundred fifty-three thousand, seven hundred twenty".