21451203455552 has 28 divisors (see below), whose sum is σ = 45841634309436. Its totient is φ = 9900555440640.

The previous prime is 21451203455551. The next prime is 21451203455597. The reversal of 21451203455552 is 25555430215412.

It can be written as a sum of positive squares in 2 ways, for example, as 9132338944576 + 12318864510976 = 3021976^2 + 3509824^2 .

It is not an unprimeable number, because it can be changed into a prime (21451203455551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12891347399 + ... + 12891349062.

It is an arithmetic number, because the mean of its divisors is an integer number (1637201225337).

Almost surely, 2^{21451203455552} is an apocalyptic number.

It is an amenable number.

21451203455552 is an abundant number, since it is smaller than the sum of its proper divisors (24390430853884).

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

21451203455552 is a wasteful number, since it uses less digits than its factorization.

21451203455552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25782696486 (or 25782696476 counting only the distinct ones).

The product of its (nonzero) digits is 1200000, while the sum is 44.

The spelling of 21451203455552 in words is "twenty-one trillion, four hundred fifty-one billion, two hundred three million, four hundred fifty-five thousand, five hundred fifty-two".