15661206450 has 288 divisors, whose sum is σ = 44611519680. Its totient is φ = 3934656000.

The previous prime is 15661206409. The next prime is 15661206461. The reversal of 15661206450 is 5460216651.

15661206450 is a `hidden beast` number, since 1 + 5 + 6 + 6 + 1 + 2 + 0 + 645 + 0 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 112670481 + ... + 112670619.

It is an arithmetic number, because the mean of its divisors is an integer number (154901110).

Almost surely, 2^15661206450 is an apocalyptic number.

15661206450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 15661206450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22305759840).

15661206450 is an abundant number, since it is smaller than the sum of its proper divisors (28950313230).

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

15661206450 is a wasteful number, since it uses less digits than its factorization.

15661206450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

It can be divided in two parts, 15661 and 206450, that added together give a triangular number (222111 = T₆₆₆).

The spelling of 15661206450 in words is "fifteen billion, six hundred sixty-one million, two hundred six thousand, four hundred fifty".