21243550140 has 72 divisors (see below), whose sum is σ = 64463490000. Its totient is φ = 5662773504.

The previous prime is 21243550123. The next prime is 21243550157. The reversal of 21243550140 is 4105534212.

21243550140 is a `hidden beast` number, since 2 + 124 + 35 + 501 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21243550123) and next prime (21243550157).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 478611 + ... + 521109.

It is an arithmetic number, because the mean of its divisors is an integer number (895326250).

Almost surely, 2^21243550140 is an apocalyptic number.

21243550140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21243550140 is an abundant number, since it is smaller than the sum of its proper divisors (43219939860).

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

21243550140 is a wasteful number, since it uses less digits than its factorization.

21243550140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45291 (or 45286 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The spelling of 21243550140 in words is "twenty-one billion, two hundred forty-three million, five hundred fifty thousand, one hundred forty".