21501553501144 has 16 divisors (see below), whose sum is σ = 40316401525320. Its totient is φ = 10750513094400.

The previous prime is 21501553501133. The next prime is 21501553501171. The reversal of 21501553501144 is 44110535510512.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 32610214 + ... + 33263029.

Almost surely, 2^{21501553501144} is an apocalyptic number.

It is an amenable number.

21501553501144 is a deficient number, since it is larger than the sum of its proper divisors (18814848024176).

21501553501144 is a wasteful number, since it uses less digits than its factorization.

21501553501144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65914050 (or 65914046 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 37.

The spelling of 21501553501144 in words is "twenty-one trillion, five hundred one billion, five hundred fifty-three million, five hundred one thousand, one hundred forty-four".