21425355158821 has 8 divisors (see below), whose sum is σ = 21549360909024. Its totient is φ = 21301351245360.

The previous prime is 21425355158761. The next prime is 21425355158839. The reversal of 21425355158821 is 12885155352412.

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 21425355158821 - 2¹⁹ = 21425354634533 is a prime.

It is a super-2 number, since 2×21425355158821² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21425355150821) 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, 28041226 + ... + 28795156.

It is an arithmetic number, because the mean of its divisors is an integer number (2693670113628).

Almost surely, 2^{21425355158821} is an apocalyptic number.

It is an amenable number.

21425355158821 is a deficient number, since it is larger than the sum of its proper divisors (124005750203).

21425355158821 is a wasteful number, since it uses less digits than its factorization.

21425355158821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918371.

The product of its digits is 3840000, while the sum is 52.

The spelling of 21425355158821 in words is "twenty-one trillion, four hundred twenty-five billion, three hundred fifty-five million, one hundred fifty-eight thousand, eight hundred twenty-one".