10638644640 has 288 divisors, whose sum is σ = 36490668480. Its totient is φ = 2604146688.

The previous prime is 10638644629. The next prime is 10638644677. The reversal of 10638644640 is 4644683601.

It is a happy number.

It is a super-2 number, since 2×10638644640² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 10638644592 and 10638644601.

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, 25390351 + ... + 25390769.

It is an arithmetic number, because the mean of its divisors is an integer number (126703710).

Almost surely, 2^10638644640 is an apocalyptic number.

10638644640 is a gapful number since it is divisible by the number (10) 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 10638644640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18245334240).

10638644640 is an abundant number, since it is smaller than the sum of its proper divisors (25852023840).

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

10638644640 is a wasteful number, since it uses less digits than its factorization.

10638644640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776 (or 755 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 42.

The spelling of 10638644640 in words is "ten billion, six hundred thirty-eight million, six hundred forty-four thousand, six hundred forty".