1661578181224 has 32 divisors (see below), whose sum is σ = 3356290516320. Its totient is φ = 766612357056.

The previous prime is 1661578181209. The next prime is 1661578181303. The reversal of 1661578181224 is 4221818751661.

It is a happy number.

It is a super-2 number, since 2×1661578181224² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (52).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2514162 + ... + 3105505.

It is an arithmetic number, because the mean of its divisors is an integer number (104884078635).

Almost surely, 2^{1661578181224} is an apocalyptic number.

It is an amenable number.

1661578181224 is an abundant number, since it is smaller than the sum of its proper divisors (1694712335096).

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

1661578181224 is a wasteful number, since it uses less digits than its factorization.

1661578181224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5622529 (or 5622525 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 52.

The spelling of 1661578181224 in words is "one trillion, six hundred sixty-one billion, five hundred seventy-eight million, one hundred eighty-one thousand, two hundred twenty-four".