21155143645144 has 8 divisors (see below), whose sum is σ = 39665894334660. Its totient is φ = 10577571822568.

The previous prime is 21155143645087. The next prime is 21155143645169. The reversal of 21155143645144 is 44154634155112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21155143645094 and 21155143645103.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1322196477814 + ... + 1322196477829.

Almost surely, 2^{21155143645144} is an apocalyptic number.

It is an amenable number.

21155143645144 is a deficient number, since it is larger than the sum of its proper divisors (18510750689516).

21155143645144 is a wasteful number, since it uses less digits than its factorization.

21155143645144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2644392955649 (or 2644392955645 counting only the distinct ones).

The product of its digits is 1152000, while the sum is 46.

The spelling of 21155143645144 in words is "twenty-one trillion, one hundred fifty-five billion, one hundred forty-three million, six hundred forty-five thousand, one hundred forty-four".