21757471285440 has 448 divisors, whose sum is σ = 76054700620800. Its totient is φ = 5226135552000.

The previous prime is 21757471285397. The next prime is 21757471285493. The reversal of 21757471285440 is 4458217475712.

It is a happy number.

It is a super-2 number, since 2×21757471285440² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 506425560 + ... + 506468520.

Almost surely, 2^{21757471285440} is an apocalyptic number.

21757471285440 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 21757471285440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38027350310400).

21757471285440 is an abundant number, since it is smaller than the sum of its proper divisors (54297229335360).

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

21757471285440 is a wasteful number, since it uses less digits than its factorization.

21757471285440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43432 (or 43422 counting only the distinct ones).

The product of its (nonzero) digits is 17561600, while the sum is 57.

The spelling of 21757471285440 in words is "twenty-one trillion, seven hundred fifty-seven billion, four hundred seventy-one million, two hundred eighty-five thousand, four hundred forty".