15505326640 has 80 divisors (see below), whose sum is σ = 36561463488. Its totient is φ = 6114705408.

The previous prime is 15505326631. The next prime is 15505326643. The reversal of 15505326640 is 4662350551.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 15505326640.

It is not an unprimeable number, because it can be changed into a prime (15505326643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1740277 + ... + 1749163.

Almost surely, 2^15505326640 is an apocalyptic number.

15505326640 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 15505326640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18280731744).

15505326640 is an abundant number, since it is smaller than the sum of its proper divisors (21056136848).

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

15505326640 is a wasteful number, since it uses less digits than its factorization.

15505326640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9206 (or 9200 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 37.

The spelling of 15505326640 in words is "fifteen billion, five hundred five million, three hundred twenty-six thousand, six hundred forty".