21634640360 has 128 divisors (see below), whose sum is σ = 50248823040. Its totient is φ = 8380416000.

The previous prime is 21634640341. The next prime is 21634640369. The reversal of 21634640360 is 6304643612.

It is a self number, because there is not a number n which added to its sum of digits gives 21634640360.

It is not an unprimeable number, because it can be changed into a prime (21634640369) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69564605 + ... + 69564915.

It is an arithmetic number, because the mean of its divisors is an integer number (392568930).

Almost surely, 2^21634640360 is an apocalyptic number.

21634640360 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 21634640360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25124411520).

21634640360 is an abundant number, since it is smaller than the sum of its proper divisors (28614182680).

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

21634640360 is a wasteful number, since it uses less digits than its factorization.

21634640360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747 (or 743 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 35.

The spelling of 21634640360 in words is "twenty-one billion, six hundred thirty-four million, six hundred forty thousand, three hundred sixty".