1669993355520 has 864 divisors, whose sum is σ = 6864136860672. Its totient is φ = 380814483456.

The previous prime is 1669993355509. The next prime is 1669993355561. The reversal of 1669993355520 is 255533999661.

1669993355520 is a `hidden beast` number, since 1 + 66 + 99 + 93 + 355 + 52 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a super-2 number, since 2×1669993355520² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1487081679 + ... + 1487082801.

It is an arithmetic number, because the mean of its divisors is an integer number (7944602848).

Almost surely, 2^{1669993355520} is an apocalyptic number.

1669993355520 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 1669993355520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3432068430336).

1669993355520 is an abundant number, since it is smaller than the sum of its proper divisors (5194143505152).

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

1669993355520 is an equidigital number, since it uses as much as digits as its factorization.

1669993355520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1849 (or 1823 counting only the distinct ones).

The product of its (nonzero) digits is 59049000, while the sum is 63.

The spelling of 1669993355520 in words is "one trillion, six hundred sixty-nine billion, nine hundred ninety-three million, three hundred fifty-five thousand, five hundred twenty".