15515632440 has 384 divisors, whose sum is σ = 64157184000. Its totient is φ = 3223745280.

The previous prime is 15515632373. The next prime is 15515632441. The reversal of 15515632440 is 4423651551.

15515632440 is a `hidden beast` number, since 1 + 5 + 5 + 15 + 632 + 4 + 4 + 0 = 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 = 15515632395 and 15515632404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15515632441) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1352569 + ... + 1363991.

It is an arithmetic number, because the mean of its divisors is an integer number (167076000).

Almost surely, 2^15515632440 is an apocalyptic number.

15515632440 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 15515632440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32078592000).

15515632440 is an abundant number, since it is smaller than the sum of its proper divisors (48641551560).

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

15515632440 is a wasteful number, since it uses less digits than its factorization.

15515632440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11472 (or 11451 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 15515632440 in words is "fifteen billion, five hundred fifteen million, six hundred thirty-two thousand, four hundred forty".