1663507261440 has 2304 divisors, whose sum is σ = 6954450048000. Its totient is φ = 364652789760.

The previous prime is 1663507261397. The next prime is 1663507261441. The reversal of 1663507261440 is 441627053661.

1663507261440 is a `hidden beast` number, since 1 + 6 + 635 + 0 + 7 + 2 + 6 + 1 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2304).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1663507261441) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 35393771497 + ... + 35393771543.

It is an arithmetic number, because the mean of its divisors is an integer number (3018424500).

Almost surely, 2^{1663507261440} is an apocalyptic number.

1663507261440 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 1663507261440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3477225024000).

1663507261440 is an abundant number, since it is smaller than the sum of its proper divisors (5290942786560).

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

1663507261440 is a wasteful number, since it uses less digits than its factorization.

1663507261440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The spelling of 1663507261440 in words is "one trillion, six hundred sixty-three billion, five hundred seven million, two hundred sixty-one thousand, four hundred forty".