21055410440 has 32 divisors (see below), whose sum is σ = 48023648280. Its totient is φ = 8306790912.

The previous prime is 21055410413. The next prime is 21055410451. The reversal of 21055410440 is 4401455012.

It can be written as a sum of positive squares in 4 ways, for example, as 12883612036 + 8171798404 = 113506^2 + 90398^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3602459 + ... + 3608298.

Almost surely, 2^21055410440 is an apocalyptic number.

21055410440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21055410440 is an abundant number, since it is smaller than the sum of its proper divisors (26968237840).

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

21055410440 is a wasteful number, since it uses less digits than its factorization.

21055410440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7210841 (or 7210837 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 26.

Adding to 21055410440 its reverse (4401455012), we get a palindrome (25456865452).

The spelling of 21055410440 in words is "twenty-one billion, fifty-five million, four hundred ten thousand, four hundred forty".