21004001225544 has 32 divisors (see below), whose sum is σ = 52525166425920. Its totient is φ = 6999311960256.

The previous prime is 21004001225531. The next prime is 21004001225587. The reversal of 21004001225544 is 44552210040012.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126276507 + ... + 126442730.

It is an arithmetic number, because the mean of its divisors is an integer number (1641411450810).

Almost surely, 2^{21004001225544} is an apocalyptic number.

21004001225544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21004001225544 is an abundant number, since it is smaller than the sum of its proper divisors (31521165200376).

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

21004001225544 is a wasteful number, since it uses less digits than its factorization.

21004001225544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252722709 (or 252722705 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 30.

Adding to 21004001225544 its reverse (44552210040012), we get a palindrome (65556211265556).

The spelling of 21004001225544 in words is "twenty-one trillion, four billion, one million, two hundred twenty-five thousand, five hundred forty-four".