21444001949640 has 128 divisors (see below), whose sum is σ = 67906532736000. Its totient is φ = 5402341525248.

The previous prime is 21444001949611. The next prime is 21444001949651. The reversal of 21444001949640 is 4694910044412.

It is a super-2 number, since 2×21444001949640² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21444001949640.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12280734 + ... + 13917773.

It is an arithmetic number, because the mean of its divisors is an integer number (530519787000).

Almost surely, 2^{21444001949640} is an apocalyptic number.

21444001949640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21444001949640 is an abundant number, since it is smaller than the sum of its proper divisors (46462530786360).

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

21444001949640 is a wasteful number, since it uses less digits than its factorization.

21444001949640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26198899 (or 26198895 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 48.

The spelling of 21444001949640 in words is "twenty-one trillion, four hundred forty-four billion, one million, nine hundred forty-nine thousand, six hundred forty".