21398650944 has 336 divisors, whose sum is σ = 65533950720. Its totient is φ = 6110213120.

The previous prime is 21398650937. The next prime is 21398650957. The reversal of 21398650944 is 44905689312.

It is a super-2 number, since 2×21398650944² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 119545447 + ... + 119545625.

It is an arithmetic number, because the mean of its divisors is an integer number (195041520).

Almost surely, 2^21398650944 is an apocalyptic number.

21398650944 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 21398650944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32766975360).

21398650944 is an abundant number, since it is smaller than the sum of its proper divisors (44135299776).

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

21398650944 is a wasteful number, since it uses less digits than its factorization.

21398650944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 51.

The spelling of 21398650944 in words is "twenty-one billion, three hundred ninety-eight million, six hundred fifty thousand, nine hundred forty-four".