21638098944 has 780 divisors, whose sum is σ = 82706230728. Its totient is φ = 5620285440.

The previous prime is 21638098943. The next prime is 21638098957. The reversal of 21638098944 is 44989083612.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

21638098944 is a `hidden beast` number, since 216 + 380 + 9 + 8 + 9 + 44 = 666.

It is a super-3 number, since 3×21638098944³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (21638098943) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1967099899 + ... + 1967099909.

Almost surely, 2^21638098944 is an apocalyptic number.

21638098944 is a gapful number since it is divisible by the number (24) 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 21638098944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41353115364).

21638098944 is an abundant number, since it is smaller than the sum of its proper divisors (61068131784).

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

21638098944 is an frugal number, since it uses more digits than its factorization.

21638098944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83 (or 23 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The spelling of 21638098944 in words is "twenty-one billion, six hundred thirty-eight million, ninety-eight thousand, nine hundred forty-four".