15551504640 has 432 divisors, whose sum is σ = 63487097856. Its totient is φ = 3439411200.

The previous prime is 15551504611. The next prime is 15551504641. The reversal of 15551504640 is 4640515551.

15551504640 is a `hidden beast` number, since 1 + 5 + 5 + 5 + 1 + 5 + 0 + 4 + 640 = 666.

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 = 15551504595 and 15551504604.

It is not an unprimeable number, because it can be changed into a prime (15551504641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2496730 + ... + 2502950.

Almost surely, 2^15551504640 is an apocalyptic number.

15551504640 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 15551504640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31743548928).

15551504640 is an abundant number, since it is smaller than the sum of its proper divisors (47935593216).

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

15551504640 is a wasteful number, since it uses less digits than its factorization.

15551504640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6286 (or 6269 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 36.

The spelling of 15551504640 in words is "fifteen billion, five hundred fifty-one million, five hundred four thousand, six hundred forty".