21542917440 has 672 divisors, whose sum is σ = 81336245760. Its totient is φ = 4811304960.

The previous prime is 21542917433. The next prime is 21542917469. The reversal of 21542917440 is 4471924512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 94902607 + ... + 94902833.

It is an arithmetic number, because the mean of its divisors is an integer number (121036080).

Almost surely, 2^21542917440 is an apocalyptic number.

21542917440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21542917440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40668122880).

21542917440 is an abundant number, since it is smaller than the sum of its proper divisors (59793328320).

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

21542917440 is a wasteful number, since it uses less digits than its factorization.

21542917440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The spelling of 21542917440 in words is "twenty-one billion, five hundred forty-two million, nine hundred seventeen thousand, four hundred forty".