21755372631552 has 960 divisors, whose sum is σ = 79937853899904. Its totient is φ = 5553027809280.

The previous prime is 21755372631533. The next prime is 21755372631557. The reversal of 21755372631552 is 25513627355712.

21755372631552 is a `hidden beast` number, since 2 + 1 + 7 + 5 + 5 + 37 + 26 + 31 + 552 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21755372631557) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 831836908 + ... + 831863060.

Almost surely, 2^{21755372631552} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21755372631552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39968926949952).

21755372631552 is an abundant number, since it is smaller than the sum of its proper divisors (58182481268352).

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

21755372631552 is a wasteful number, since it uses less digits than its factorization.

21755372631552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26279 (or 26260 counting only the distinct ones).

The product of its digits is 13230000, while the sum is 54.

The spelling of 21755372631552 in words is "twenty-one trillion, seven hundred fifty-five billion, three hundred seventy-two million, six hundred thirty-one thousand, five hundred fifty-two".