1661981699430 has 96 divisors (see below), whose sum is σ = 4729836646080. Its totient is φ = 402396560640.

The previous prime is 1661981699381. The next prime is 1661981699453. The reversal of 1661981699430 is 349961891661.

1661981699430 is a `hidden beast` number, since 1 + 6 + 6 + 198 + 1 + 6 + 9 + 9 + 430 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11572050 + ... + 11714789.

It is an arithmetic number, because the mean of its divisors is an integer number (49269131730).

Almost surely, 2^{1661981699430} is an apocalyptic number.

1661981699430 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1661981699430 is an abundant number, since it is smaller than the sum of its proper divisors (3067854946650).

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

1661981699430 is a wasteful number, since it uses less digits than its factorization.

1661981699430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23286926 (or 23286923 counting only the distinct ones).

The product of its (nonzero) digits is 15116544, while the sum is 63.

The spelling of 1661981699430 in words is "one trillion, six hundred sixty-one billion, nine hundred eighty-one million, six hundred ninety-nine thousand, four hundred thirty".