21253556425554 has 64 divisors (see below), whose sum is σ = 47347772400000. Its totient is φ = 7066885573440.

The previous prime is 21253556425531. The next prime is 21253556425583. The reversal of 21253556425554 is 45552465535212.

21253556425554 is a `hidden beast` number, since 2 + 1 + 2 + 5 + 3 + 5 + 5 + 64 + 25 + 554 = 666.

It is a super-2 number, since 2×21253556425554² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 21253556425554.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 55560664 + ... + 55941884.

It is an arithmetic number, because the mean of its divisors is an integer number (739808943750).

Almost surely, 2^{21253556425554} is an apocalyptic number.

21253556425554 is an abundant number, since it is smaller than the sum of its proper divisors (26094215974446).

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

21253556425554 is a wasteful number, since it uses less digits than its factorization.

21253556425554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383800 (or 383794 counting only the distinct ones).

The product of its digits is 36000000, while the sum is 54.

The spelling of 21253556425554 in words is "twenty-one trillion, two hundred fifty-three billion, five hundred fifty-six million, four hundred twenty-five thousand, five hundred fifty-four".