21521440525423 has 8 divisors (see below), whose sum is σ = 21893508720000. Its totient is φ = 21149615598168.

The previous prime is 21521440525411. The next prime is 21521440525439. The reversal of 21521440525423 is 32452504412512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21521440525423 - 2²¹ = 21521438428271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21521440525483) 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, 60638361 + ... + 60992242.

It is an arithmetic number, because the mean of its divisors is an integer number (2736688590000).

Almost surely, 2^{21521440525423} is an apocalyptic number.

21521440525423 is a deficient number, since it is larger than the sum of its proper divisors (372068194577).

21521440525423 is a wasteful number, since it uses less digits than its factorization.

21521440525423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121633661.

The product of its (nonzero) digits is 384000, while the sum is 40.

Adding to 21521440525423 its reverse (32452504412512), we get a palindrome (53973944937935).

The spelling of 21521440525423 in words is "twenty-one trillion, five hundred twenty-one billion, four hundred forty million, five hundred twenty-five thousand, four hundred twenty-three".