10661813640 has 96 divisors (see below), whose sum is σ = 34720920000. Its totient is φ = 2837404800.

The previous prime is 10661813597. The next prime is 10661813683. The reversal of 10661813640 is 4631816601.

10661813640 is a `hidden beast` number, since 1 + 0 + 6 + 6 + 1 + 8 + 1 + 3 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (10661813597) and next prime (10661813683).

It is a super-2 number, since 2×10661813640² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 10661813595 and 10661813604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 149965 + ... + 209315.

It is an arithmetic number, because the mean of its divisors is an integer number (361676250).

Almost surely, 2^10661813640 is an apocalyptic number.

10661813640 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 10661813640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17360460000).

10661813640 is an abundant number, since it is smaller than the sum of its proper divisors (24059106360).

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

10661813640 is a wasteful number, since it uses less digits than its factorization.

10661813640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59867 (or 59860 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The spelling of 10661813640 in words is "ten billion, six hundred sixty-one million, eight hundred thirteen thousand, six hundred forty".