21425355156798 has 64 divisors (see below), whose sum is σ = 47783148445440. Its totient is φ = 7116122613600.

The previous prime is 21425355156797. The next prime is 21425355156853. The reversal of 21425355156798 is 89765155352412.

It is a happy number.

21425355156798 is a `hidden beast` number, since 2 + 1 + 4 + 2 + 5 + 3 + 551 + 5 + 6 + 79 + 8 = 666.

It is a super-2 number, since 2×21425355156798² (a number of 27 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21425355156797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30882808 + ... + 31568948.

It is an arithmetic number, because the mean of its divisors is an integer number (746611694460).

Almost surely, 2^{21425355156798} is an apocalyptic number.

21425355156798 is an abundant number, since it is smaller than the sum of its proper divisors (26357793288642).

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

21425355156798 is a wasteful number, since it uses less digits than its factorization.

21425355156798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688230 (or 688224 counting only the distinct ones).

The product of its digits is 90720000, while the sum is 63.

The spelling of 21425355156798 in words is "twenty-one trillion, four hundred twenty-five billion, three hundred fifty-five million, one hundred fifty-six thousand, seven hundred ninety-eight".