21244235507640 has 192 divisors, whose sum is σ = 71611569993600. Its totient is φ = 5664288569472.

The previous prime is 21244235507629. The next prime is 21244235507653. The reversal of 21244235507640 is 4670553244212.

21244235507640 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 4 + 23 + 550 + 76 + 4 + 0 = 666.

It is a super-3 number, since 3×21244235507640³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 66743991 + ... + 67061529.

It is an arithmetic number, because the mean of its divisors is an integer number (372976927050).

Almost surely, 2^{21244235507640} is an apocalyptic number.

21244235507640 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 21244235507640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35805784996800).

21244235507640 is an abundant number, since it is smaller than the sum of its proper divisors (50367334485960).

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

21244235507640 is a wasteful number, since it uses less digits than its factorization.

21244235507640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324448 (or 324432 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 45.

The spelling of 21244235507640 in words is "twenty-one trillion, two hundred forty-four billion, two hundred thirty-five million, five hundred seven thousand, six hundred forty".