21451603144 has 16 divisors (see below), whose sum is σ = 40327887600. Its totient is φ = 10697499792.

The previous prime is 21451603141. The next prime is 21451603181. The reversal of 21451603144 is 44130615412.

It is not an unprimeable number, because it can be changed into a prime (21451603141) 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, 3534502 + ... + 3540565.

It is an arithmetic number, because the mean of its divisors is an integer number (2520492975).

Almost surely, 2^21451603144 is an apocalyptic number.

It is an amenable number.

21451603144 is a deficient number, since it is larger than the sum of its proper divisors (18876284456).

21451603144 is a wasteful number, since it uses less digits than its factorization.

21451603144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7075452 (or 7075448 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

It can be divided in two parts, 2145 and 1603144, that added together give a square (1605289 = 1267²).

The spelling of 21451603144 in words is "twenty-one billion, four hundred fifty-one million, six hundred three thousand, one hundred forty-four".