21420573237481 has 16 divisors (see below), whose sum is σ = 23387759659008. Its totient is φ = 19456701754000.

The previous prime is 21420573237461. The next prime is 21420573237491. The reversal of 21420573237481 is 18473237502412.

It is a cyclic number.

It is not a de Polignac number, because 21420573237481 - 2¹⁹ = 21420572713193 is a prime.

It is a super-2 number, since 2×21420573237481² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21420573237421) 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, 94479306 + ... + 94705756.

It is an arithmetic number, because the mean of its divisors is an integer number (1461734978688).

Almost surely, 2^{21420573237481} is an apocalyptic number.

It is an amenable number.

21420573237481 is a deficient number, since it is larger than the sum of its proper divisors (1967186421527).

21420573237481 is a wasteful number, since it uses less digits than its factorization.

21420573237481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233732.

The product of its (nonzero) digits is 2257920, while the sum is 49.

The spelling of 21420573237481 in words is "twenty-one trillion, four hundred twenty billion, five hundred seventy-three million, two hundred thirty-seven thousand, four hundred eighty-one".