1661504724000 has 2016 divisors, whose sum is σ = 7149147406128. Its totient is φ = 377726976000.

The previous prime is 1661504723987. The next prime is 1661504724037. The reversal of 1661504724000 is 4274051661.

1661504724000 is a `hidden beast` number, since 1 + 66 + 150 + 47 + 2 + 400 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 36583447824 + 1624921276176 = 191268^2 + 1274724^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 335 ways as a sum of consecutive naturals, for example, 5998211862 + ... + 5998212138.

Almost surely, 2^{1661504724000} is an apocalyptic number.

1661504724000 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 1661504724000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3574573703064).

1661504724000 is an abundant number, since it is smaller than the sum of its proper divisors (5487642682128).

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

1661504724000 is a wasteful number, since it uses less digits than its factorization.

1661504724000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 315 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

Adding to 1661504724000 its reverse (4274051661), we get a palindrome (1665778775661).

The spelling of 1661504724000 in words is "one trillion, six hundred sixty-one billion, five hundred four million, seven hundred twenty-four thousand".